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Category: Repair

RAMLink reproduction labels are offered by Corei64 and I decided to give it a go since my RAMLink label was worn. The color difference between the original and reproduction label is only due to the camera. Isopropyl alcohol and eraser was used to get the old sticker remains off.
Wanted: New GAL:s for my RAMLink, if anyone has successfully cloned them, please let me know.

Original RAMLink label.

Replacement label by Corei64, shipped promptly and very well packaged.


Final result, pleased with the result and quality of the label.

For the Eagle Term II v1.9 Sourcecode I had to repair and recap a SFD-1001 drive.

A very common issue on these drives are leaking capacitors causing damage on the motor control PCB. These should be replaced as soon as possible.

A few important notes on the way:
1. The screws holding the rotor(magnet) and especially the PCB screws are ridiculously tight, it’s almost as they are not loosening up at all. Make sure to have an exact size screwdriver and use correct amount of force to unscrew them, you don’t want to end up with destroyed screw heads.
2. There is a fragile flat cable on the underside, be aware of it before lifting up the PCB.


Remove the three screws and lift the rotor(magnet).


Remove the four screws holding the PCB marked with red circles and remove the spacers (mine had three of them).


Desolder the two connectors marked with red squares.


Close up of the cable in the lower left corner, be careful desoldering it.


Drive motor control PCB.


Original capacitor values and sizes. h=height, d=diameter, r=lead spacing.


Component list and manufacturer part numbers, some caps are rated higher than the original voltage value. There is limited space for the capacitors but the components above will fit. Capacitors C13/C14/C15 are bipolar.


Part numbers for IEEE-488 Connectors also available from DigiKey.



SFD-1001 Head Resistance check.

Resistance RW1 or RW2 to CT : 37 ± 30% Ohms
Resistance ERASE to CT : 8.0 ± 30% Ohms
Information above from 8250LP SFD-1001 Disk Drive Technical Manual


Measurements from the field on working drives for reference.


The C128 was given a double-sized CHARROM which consists of the C128 characterset and the C64 characterset, both used in respective mode. The fonts differ in lowercase b, d, f, h, i, j, k, l, m, s, t, u, w and y (all C128 chars are equal to the plus/4 except for the m). Early C128 prototypes had only one font but there were some compatibility issues so they had to include the original font to be used in the C64 mode.

C64 characterset vs C128 characterset
National (SE/FI/DK/NO etc) models use the same font between C128 and C64 mode because the other bank is used to store the national characterset. You can switch between the charactersets using the CAPS LOCK-key. National models also have a 2764 ROM and a 2364 to 2764 adapter, you can see the differances in an earlier post C128 vs C128d motherboard. The upper picture is a US C128 and the lower picture shows a SE/FI C128. Depending on the region, the CAPSLOCK-key can have different printings; “CAPS LOCK”(US), “ASCII/DIN”(DE), “CAPS LOCK ASCII/CC”(SE/FI) and possibly some more.

If the CHARROM(U18) needs replacement, the pinout is a 2364(8K) ROM. You can replace it with a 2764 using 2364 to 2764 adapter (note that there is not much space under the RF-shield).


National modifications for C128

SE/FI machine. The brown wire connects jumper “J7” and CHARROM pin 21 together allowing CHARROM bankswitching using the CAPS LOCK key.

Closeups of the modifications. CHARROM lifted out of the socket to see where the bankswitching wire is connected. The trace near C19 is cut and the wire connected to the rightmost pad of J7.

C128 CHARROM. SE/FI characterset with a factory 2364-to-2764 adapter.

C128 Character ROM, U18, partnumbers
390059-01 US (2364)
315079-01 DE (2364)
315079-02 DE
325173-01 CH
325175-01 DK
325175-02 DK
325171-01 ES
325167-01 FR/BE/IT
325178-01 NO
325181-01 SE/FI


I have repaired a fair amount of drives, and every time I find myself loading a test or a diagnostic software from disk. This is a bit of a contradiction since the drive being tested, or repaired, might not even be able to load a program. I also have a variety of tools for different purposes and wanted to have everything in one place.


This is why i created a 1541 Diagnostic Cartridge.


The challenge was to get all these tools to fit into a 8K cart. I wanted to keep the hardware simple and a 16K cart would have overwritten the Basic interpreter.

Therefor I have optimized both code and visual on the tools to keep the size down. Some tools are old, others were written from scratch and a few I rewrote in machine code instead of basic. A couple of the tools are still in Basic, but optimized.

The cartridge is an 8K ROM at $8000-$9FFF

You can also use RESTORE to return to the menu.

You may need to send a “I0:” or turn the drive off/on before running further tests if an previous error has occurred.

Occasionally I get questions about alignment and aligning the drive. There are some differences of opinion how to align a diskdrive, my personal view, and how I do it, is to use a special analogue disk and a dual trace oscilloscope. The analogue disk is a factory produced disk and has patterns written on specific tracks. An analogue alignment disk can not be duplicated.

1541 Diagnostic Cartridge Alignment Check. This program was distributed with a computer magazine and gives a quick drive alignment health instead of hooking up an oscilloscope. The program was completely disassembled, compacted (code and texts) and disk routines rewritten to share I/O routines just to fit onto the cart with the other tools.

The Alignment check program can (I, however, do not recommend doing it this way) be used to adjust the alignment but it will only be as accurate as the drive, or system, the disk was written with.

The two first columns should be identical, otherwise the alignment is off by a whole track(or more), most often this indicates an incorrectly positioned head stop. The third column indicates how well the drive can read data off each track, its alignment, and should be 100%, or atleast very close to. Fourth column is between tracks (or half tracks), this value can fluctuate a bit even on a well aligned drive. The 1541 allows for some tolerance and therefore some values can be within reasonable limits.

It is very seldom when you actually need to align a drive for proper functionality. If the drive works in daily usage and does not make noise or do continious re-reads or searches it is probably ok. If a drive fails to read disks, begin with cleaning the head and lubricate the rails. If this does not help, the R/W head might be damaged, quite often seen on the Mitsumi D500 mechanism. You can verify it by measuring the R/W head using an ohm-meter. Remember that a slightly misaligned drive is probably able to format and read its own formatted disk.

Most important, if it works, don’t fix it 😉

Recommended reading : Commodore Diskette Diagnostic Manual Version 2 (3140451-01) and Commodore 1541 Troubleshooting & Repair Guide (SAMS)


Update 2020.09: C64iSTANBUL designed a PCB, You can find it on pcbway 🙂
Update 2019.12: A few words about alignment.
Update 2019.12: TFW8B is selling their version of the cartridge.
Update 2017.09: The Cartridge is also available at the Protovision shop.
Update 2015.12: Upon request from their customers, The Shareware PLUS Commodore 64 & 128 Blog asked me if they could offer the 1541 diagnostic cartridge in their product sortiment.



1541 Diagnostic PCB by C64iSTANBUL. Looking great, thanks ! 🙂


This post spawned out of a discussion at a facebook group about the commodore diagnostics reporting errors when using custom kernals. I decided to modify the kernal detection routine to identify good known kernals from a checksum table. Thanks to Jonny Hylander, Fredric QJ Blåholtz and Krister Andersson for ideas and suggestions.

586220+ : Initial version. Disassembly and kernel identification routines by

586220+ v0.4 : Marty/Radwar sent a huge list of kernal checksums. This version is able to identify a staggering 49 different kernals, for example Professional Dos, RapiDos, DolphinDos and Speeddos. Download the v0.4 sourcecode for a full list.

586220++ v0.5 SX-64 Tape Port check removal : KiWi at sent me a version which works correctly on the SX-64. Scroll down for the download and sourcecode. See his page here.

586220++ v0.5 Expanded window for paddle test by Sven Arke. Klick here.

586220* Proper chip number display for SX-64 and C-64 by Ted Saari. Readme.

See Diagnostic Carts and Manuals for information about the harness for this ROM.

2020-06 : giox sent me an updated standalone program which identifies 137 kernals. There is an ID clash (which can be expected at some point) for 901246-01(4064 Kernal) and Armageddon.


Sourcecode for diag586220+ and original disassembly of the 586220 diagnostic. Compare these two files to see how the implementation was made.
Diag586220+ v0.4 by Marty / Radwar. It identifies 49 different kernals.
Standalone ROM Checksum program with diag586220+ v0.4 tables
Standalone ROM Checksum program for 137 kernals, thanks to giox for the work!
Diag586220++ v0.5 by KiWi /
Diag586220++ v0.5 Paddle Update 08/2017
Diag586220* Proper chip number display for SX-64 and C-64 by Ted Saari 07/2018
Sourcecode for Diag586220*




The diagnostic 586220 does a checksum on the kernal ROM to verify if it is ok. It will only identify the original CBM ROMs. All other (even good, for example JiffyDos) kernals will be marked as “BAD”.

The 586220 was used since i have done an reassembly/disassembly of it earlier.

Code to calculate the checksum.

Depending on $FF80(Kernel revision) the checksum is either $E0 or $E1. This determines if Kernal is marked as “OK” or “BAD” by the diagnostic test.

I remembered that the C128 diagnostic cart displays the checksum. When running the C128 diagnostic(789010) the checksum on the C64 Kernal is reported as $D4. After investigating the code, which is identical to the one above except for the fact that only $1F00 of memory is checked, this is probably due to $FF00-$FF04 belong to the MMU.

We shared ideas about how this would be accomplished, but also noticed that some of the different kernals generated the same checksum. This might be deliberate for them to pass a diagnostic test.


All code below is compatible with 64tass (i.e. Turbo Assembler compatible).

The new checksum routine. To make a distinction, the address lowbyte is xor:ed and therefor not resulting in an identical checksum.



…I made a program that can identify the kernal ROM.


A table is used for the checksum and a pointer(.word) to the matching ROM name. You can easily add new checksums and ROMs to the code.




Incorporate the checksum with Diagnostic 586220
The goal is to replace the original checksum routine with the code above.

As we can see in the disassembly, the routine for ROM tests are at $890E. Further investigations reveal that code between $890E and $8A44 can be replaced. This area also has the routines to check BASIC and CHARACTER ROM.


Checksum routine is located a few lines below $8926.

After inserting the code, you can now assemble(compile) the code with c64tass. I won’t go into details about the code itself, but it is presented and downloadable further down on the page.


The output file (.o64) can now be written to an eprom. Skip the two first bytes (0x00, 0x80) which is the loadingadress of the file.

You can also test the cart in vice by converting it to a crt. Cartconv.exe is included with the Vice emulator.


586220+ diagnostic, it is now possible to identify the kernal ROM.


The new checksum code.

Checksums for BASIC and CHAR are also displayed.



The C128 Cartridge functionality is different than in the C64. Maximum size has been doubled to 32K and an EPROM socket (U36) has been provided inside the machine in addition to the cartridge port.

An external cartridge is referred as “External(Function ROM)” and the internal EPROM socket is referred as “Internal(Function ROM)”. This will focus on how to create an external cartridge.

A 8-bit machine can only “see” 64K at a time, and the same goes for the C128.

There are two areas in the C128 memory where cartridges can be located; the MID ($8000-$BFFF) and HIGH ($C000-FFFF). A cartridge can be started up in either these 16K areas or single 32K cartridge can be used. It is possible to have both an internal “cartridge” and an external cartridge installed, but the external has preference over the internal.

C128 memory is managed by a chip called the Memory Management Unit(MMU) and does not use the PLA(GAME/EXROM lines) like the C64.

MMU is controlled by its primary registers at $D500- and its secondary registers at $FF00-. The secondary registers are available to make it possible to switch out the I/O area at $D000-DFFF and still be able to access the MMU. This creates a memory “hole” at $FF00-$FF04 which can not be used for code.

Note that both cartridge areas (MID and HIGH) are always switched in together. If you set up a 16K cartridge in MID area and want to access Kernal routines, you will need to bank in Kernal at the HIGH space.


Cartridge Autostart
When a C128 is booted, a cartridge presence is checked. First it checks if GAME or EXROM lines are low. If this is the case, a C64 mode cartridge is connected and the machine starts in C64 mode. Otherwise the C128 memory is checked for an identifier(“CBM”) string at $8007 and $c007, this is done both for the external and internal slots. The banks are checked in the following order: External Mid, External High, Internal Mid and Internal High.


Code at $E27A- is used to verify if a cartridge is inserted:


Cartridge/ROM identifier byte
Position $8006 is the identifier byte for the cartridge which determines if the cartridge should be autostarted, it has three options:

$00 : Do not autostart ROM/cartridge.
$01 : Autostart immediately using the cartridge cold-start vector.
>$01 : Autostart through BASIC cold-start sequence ($FF commonly used for >$01).

BASIC will not be initialized when having $01 as identifier byte.


16K Cartridge code example at $8000(MID) with Kernal ROM banked in.


16K Cartridge example at $8000(MID) with BASIC code copied and executed.

This example will copy BASIC code from the cartridge ROM to BASIC_START ($1c01) and RUN it. Identifier byte is set to $FF, which initializes BASIC before running the cart/ROM.
Pay attention to the address basic_end = $1c17 in the example. It is the size of the BASIC program and will cause trouble with the BASIC interpreter if not set properly. It can be automated with a “better” copy-routine but I wanted to write it out in the example.


Test the code(s) above with WinVICE:


C128 16K Cartridge $8000-$BFFF (MID)

You can add another 27128 and connect RH to /OE on that chip to get 32K.


Update 2021-07: Clarified details about the cartridge/ROM identifier byte and added second example.

To create a cartridge for your C64 in the simplest form, is wiring a 8K ROM to the expansion port.

The CPU can only see a maximum of 65536 bytes. Adding a cartridge will not give you additional memory, instead it will replace memory at $8000, $A000 or $E000 depending on how ROML, ROMH, EXROM and GAME lines are being handled in the expansion port.

It is possible to bank in and out ROML/ROMH areas to gain access to different banks or RAM. This is how EasyFlash cartriges provide 1MB to the C64, it however only sees 16K of the 1MB at a time.



There are basically three types of cartridges for the C64:

8K Cartridge, $8000-$9FFF (ROML).
GAME = 1, EXROM = 0
ROML is read only. Basic ROM and Kernal ROM are available.

16K Cartridge, $8000-$9FFF / $A000-$BFFF (ROML / ROMH).
GAME = 0, EXROM = 0
ROML/ROMH are read only, Basic ROM is overwritten by ROMH.

16K Cartridge, $8000-$9FFF / $E000-$FFFF (ROML / ROMH). Ultimax mode.
GAME = 0, EXROM = 1
Ultimax mode is an emulation of the Japanese CBM machine called “MAX”. It is a predecessor of the C64 with less RAM. In Ultimax mode ROMH replaces the kernal at $E000. You do not need ROML for a cartridge to function and can be left out.



Cartridge autostart
When starting up, the CPU will load the reset vector from $FFFC/$FFFD into the program counter and continue from there. If a normal cartridge is present, it executes the kernal and checks for a cartridge identifier string.

Kernal will look for the string “CBM80” at $8004- and will do a “JMP($8000)” if found.

If an Ultimax cartridge is inserted, the kernel is overwritten by ROMH and therefor $FFFC/$FFFD must point to your code.

8/16K Cartridge code example



Test the code above with WinVICE:



Commodore 64 Expansion port pinout:

Expansion Port



8K Cartridge $8000-$9FFF


16K Cartridge $8000-$BFFF

16K Cartridge $8000-$BFFF (Single chip version)

16K cartrige at $8000-$bfff

A 27128 chip and a two input AND gate consisting of two diodes and a resistor. You can also use a 74LS08.


8K Cartridge $e000-$FFFF (Ultimax, no ROML at $8000)
You can create a 16K Ultimax cartridge by adding a 8K EPROM and connect it to ROML($8000-$9FFF).

8K cartrige at $e000 (ultimax)


Check out SukkoPera’s Open Hardware 8Kb Cartridge at:


Update 2015.12: Corrected an error in the 16K cart schematic. EXROM/GAME should be connected and not IO2/EXROM. Text was correct but QC slipped on the drawing. Thanks to mATE for notifying me about it.
Update 2016.01: Updated Ultimax cart schematic with $e000-$ffff. Text was correct but again QC has slipped on the drawing. Thanks to Bart for the heads up.
Update 2017.12: Added single chip 16K schematic.

Replacing a 2364 ROM with a 2764 EPROM requires an adapter. You can use a 2364 to 27128 adapter to be able to switch between two different ROMs (ex: cbm original and a floppy speeder kernal).

This adapter is suitable for C64/128 and 1541 ROM replacement, earlier machines may need another type of adapter.


2364 to 2764 adapter



2364 to 27128 adapter

2364 to 27128

R1 = 4.7k ohm
J1 = Switch


C64 (Breadbox)

Kernal: 8K 2364 ROM chip 901226-0x, where revision number is “x”. Available revisions are : 1,2 or 3(latest).
0000-1FFF = Kernal ROM (901227-03), located at $E000-$FFFF.

This is a 2364 ROM and is NOT pincompatible with a 2764. You will need an adapter to replace the ROM with an EPROM.


C64C (C64E, Short board)

Basic and Kernal combined on a 16K chip, U4, 251913-01.
0000-1FFF = Basic ROM (same as 901226-01), located at $A000-$BFFF
2000-3FFF = Kernal ROM (same as 901227-03), located at $E000-$FFFF
Pincompatible with a 27128 eprom.


Use 251913-01 ROM or combine basic and kernal yourself:


Custom C64-E ROM (32K, switchable between standard and dolphin dos2):

0000-1FFF = Basic ROM (same as 901226-01), located at $A000-$BFFF
2000-3FFF = Kernal ROM (same as 901227-03), located at $E000-$FFFF
4000-5FFF = Basic ROM (same as 901226-01), located at $A000-$BFFF
6000-7FFF = Dolphin DOS 2 Kernal, located at $E000-$FFFF




Diagnostic cartridges for the Commodore 64 / 128.

A bunch of diagnostic carts. Some of the material below is from the web and some of them are from my own collection.

You will probably be fine with the C64 Dead Test (Rev 781220) and C64 Diagnostic Kit 326070-1 (Rev 586220/588220) for the C64. Use the C64 Dead Test if you got a blank(black) screen, it will flash the border according to which RAM circuit is broken.

If you got a C128 with a blank(blank) screen you can use the C64 Dead Test to find faulty (low) memory. When the C64 side is working, use the C128 Diagnostics to verify the upper memory. It is also possible to rewire the high and low memory and then give the C64 Dead Test a second run. C128 Diagnostic Carts use the same harness as the C64 Rev.586220 (326070-01) but with a different keyboard adapter.

586220 Harness
Check out Sven’s page for an excellent resource about the harness! He has also remedied a problem where the keyboard dongle falsifying passes the user and control port tests. Otherwise you must run the test a second time without the keyboard dongle, this is not mentioned in the manual.

Testing in VICE
You can test the carts in vice:
C64: x64.exe -cartcrt [cartname].crt
C128: x128.exe -extfunc -extfrom [romname].bin

2014-11: I have now included both C128 and C128D keyboard connector schematics for Rev.785260 to avoid misunderstandings. There are also some notes about the connector at position 1.4.8 in the manual.
2015-01: Added disassembly of the C-64 Diagnostic Rev 4.1.0. This was a bit tricky to disassemble(reassemble) as it crossreferences code between $8000/$1000.
2015-01: Added C-64 Diagnostic (Box) (324528-02). Thanks to SLC and Zoran.
2015-01: Added C-128 DCR Integral Diag 1.0 and C-128 Diag Rev.588121. Thanks to Zoran.
2015-01: Thanks to Boulderdash for the info about the C128 Serial Adapter.
2015-10: On request, I made a disassembly of the C64 Diag 781220 deadtest.
2016-11: Added Rossmöller / Roßmöller Doctor64 diagnostic. Thanks to DOC64 and Sierohpätsch.
2018-12: Added C-64 Diagnostic Rev 4.1.1 and Import Test Diag.
2018-12: Added C-64 Diagnostic Rev 3.7.3. At a meeting held by the Dutch Commodore Club, Jeroen Vlasveld noticed a diagnostic harness not present on this page. He sent over the diagnostic Rev 3.7.3 ROM, a picture and a schematic of the harness. Thanks!
2020-04: Added information about the diagnostic falsifying passing tests due to the keyboard dongle and a link to Sven’s page for the 586220 harness. Thanks to Sinan and Sven for the information.
2020-05: Added download for C128 Diagnostic 588121B which will work as internal (U36) ROM and external function/cart ROM. Thanks to Bart ( for the update.
2020-05: Together with Bart, we patched more C128 diagnostics carts to work as internal (U36) ROM and external function/cart ROM. Added download for C128 Diagnostic Rev 789010JB.
2020-05: Added C64GS Diagnostic Rev 1.1 and Rev 2.0 ROM:s.
2020-09: Added 4 Burn-In ROMs.
2020-10: Added C64 Burn In R2.1. Thanks to Jeroen Vlasveld.


Don’t miss the updated Diagnostic 586220 with kernel detection and other fixes.

Additional credits:
Peter Schepers, Nicolas Welte, DLH’s Commodore Archive, SLC, Zoran, Doc64, Sierohpätsch, Jeroen Vlasveld (, Dutch Commodore Club, Bart (


C-64 Dead Test Kit (CBM 314139-03)

dead test
Rev. 781220. Located at $E000 in memory(ultimax) and boots before kernal ROM.

Cartridge ROM: C64 Dead Test Rev 781220 Diagnostic Cartridge (314139-01)
Manual: C64 Dead Test Diagnostic Manual (314139-02)



C-64 Diagnostic Assembly Kit (CBM 326070-01)


Rev. 586220 (c64)  and 588220 (sx64)

Located at $8000 in memory and requires a harness (some tests work without the harness).
Note: There are atleast 3 variations of the schematic on the net, two of them are missing an interconnected wire in the casetteport.

Cartridge ROM: C64 Diagnostic Rev 586220/588220 Cartridge (314061-01)
Manual: C64 Diagnostic Instruction and Troubleshooting Manual (314061-05)
Harness Schematic: C64 Diagnostic Harness Schematic (314061-02/03/04)

I disassembled the cartridge for studying purposes. It can be compiled(assembled) with 64tass.



C-64 Diagnostic Rev 3.7.3, Rev 4.1.0, Rev 4.1.1 and Import Test Diag
C-64 GS Diagnostic Rev 1.0, Rev 2.0

Located at $8000- in memory and use harness 251169-02.

C-64/C-64 GS Diagnostic Rev x ROMs. I dug out all diagnostics visually alike and disassembled them, after aligning code and comparing routines it became obvious these four were from the same code base. Import Test Diag is modified to work without a harness. C-64 GS Diagnostics are also on the same code base, some tests omitted due to the fact it does not have all peripheral ports.



C-64 Diagnostic (Box) (CBM 324517-02)

Located at $8000- in memory and uses its own harness. See also Roßmöller Doctor64 below.
Cartridge ROM: Prog. for Diagnostic Box (324528-02)

Roßmöller Doctor64

Located at $8000- in memory and uses same harness as Diagnostic Box (324528-02).
The Roßmöller will give a false “Interrupt BAD” on C64C models. Interesting is that the Diagnostic Box (324528-02), which can be found on a Commodore spare parts list, has identical check routines as Doctor64 except for the Interrupt part.



C-128 Diagnostic Rev. 588121

Rev. 588121
Uses the same harness as the C64 Rev.586220 (326070-01).

Modified to work as internal (U36) and external (Cart) function ROM.



C-128 Diagnostic Assembly Kit (314060-01)


Rev. 785260
Uses the same harness as the C64 Rev.586220 (326070-01).

Cartridge ROM: C128/128D Diagnostic Rev 785260 Cartridge (314061-06)
Manual: C128 Diagnostic Instruction and Troubleshooting Manual (314061-09)
C128 Diagnostic Keyboard Adapter (314061-07).
C128D Diagnostic Keyboard Adapter (314987-01).
Note: C128 Serial Port Connector has Pins 1 and 5 connected.



C-128 Diagnostic Rev. 789010


Rev. 789010
Uses the same harness as the C64 Rev.586220 (326070-01).

Modified to work as internal (U36) and external (Cart) function ROM.


C-128 Diagnostic Rev 1.1 and 1.4 (325099-01)

C-128 Diagnostic Rev 1.x Uses its own Cart and harness.



C-128 DCR Integral Diag 1.0 (325109-01)

Cartridge ROM: C-128 DCR Integral Diag 1.0 ROM (325109-10)


C-64 “Burn In”
Burn-in is the process by which components of a system are exercised.

Even though the screenshot says diagnostic, these ROMs come from cartridges labeled “Burn In”. The basecode is the same but there has been a lot of patching/adding/omitting done.

C64 Burn In Cart – Screens 1,2,3. (Keys F1/F3 to loop/continue test).
C64 Burn In “Hot Burn In” – Screens 3,4,5. (F1/F3/F5-keys have been disabled).
C64 Burn In “Rev 7.2” – Screens 3,4,5. (F5 key to skip test).
C64 Burn In “Final Rev 3.0” – Screens 3,4,5,6. (F5 key to skip test). Diagnostic routines in this ROM are identical to the ones in “C-64 Diagnostic Rev 3.7.3”.


C-64 Burn In R2.1