DEAD TEST for Commodore VIC20 / VC20 !
PRICE --> 24€ + shipping (Paypal friend)
This is a "DEAD TEST" cartridge very useful in order to check memory or ROMs problems. It is fully compatible with both VIC20 version (PAL & NTSC).
FEATURES
When powering on the program will detect if you are using PAL or NTSC and set the appropriate video modes. Tests will then be run on the lower RAM, followed by video RAM.
If there is a fault found with any of these tests the code will display the error and also show the chip number.
Following the routine test:
On each 1Kb of RAM the upper and lower nibble of data is checked, followed by address and data lines. If the test fails on the nibble then data/address lines will not be tested and the code will then move onto the next block.
On each failure the status screen will also be updated with the chip number that is faulty.
Following these tests the CRC value is calculated for each ROM (Basic, Char, Kernal) and if a matching version is found the status page will be updated.
The code currently checks for
INTERPRETING THE OUTPUT
EXAMPLE 1
When testing the main RAM, its broken down into 4 tests
EXAMPLE 2
When testing the RAMa / RAMb / RAMc / RAMd
EXAMPLE 3
When testing the RAMa / RAMb / RAMc / RAMd
PRICE --> 24€ + shipping (Paypal friend)
This is a "DEAD TEST" cartridge very useful in order to check memory or ROMs problems. It is fully compatible with both VIC20 version (PAL & NTSC).
- This diagnostic cartridge is equipped with 1kByte of RAM where CS1 is hardwired to BLK5 (reference RAM1)
- The control lines in the software for the external ram (RAM2 / RAM3 / BLK1 / BLK2 / BLK3 on cartridge) have been deleted because they are not needed as the cartridge only mounts 1Kbyte and is configured on BLK5. For this reason the "XX" present under the heading "RAM1" are not to be considered.
- This cartridge allows you to check/verify the RAM banks of the VIC20 (internal) and BASIC / CHARACTER / KERNAL chips
- Software is able to understand if it is running on a VIC PAL or NTSC: therefore there is no need to set any jumper.
- The first image displays a VIC20 with all memory banks and the Romset running. In the last image as an example we see instead a problem on the BASIC chip (damaged / faulty). In the event of a problem on the ram banks they will be indicated with the symbol "X" and the faulty chip will be highlighted
FEATURES
When powering on the program will detect if you are using PAL or NTSC and set the appropriate video modes. Tests will then be run on the lower RAM, followed by video RAM.
If there is a fault found with any of these tests the code will display the error and also show the chip number.
Following the routine test:
- Lower RAM $0000 - $03FF
- Video Colour RAM $9400 - $97FF
- BLK1,2,3 RAM from expansion cartridges (as said before...only RAM1 will be performed,other not necessary because not present)
- 1Kb Expansion $0400-$07FF - RAM1
- 1Kb Expansion $0800-$0BFF - RAM2 (as said before...not performed,not needed)
- 1Kb Expansion $0C00-$0FFF - RAM3 (as said before...not performed,not needed)
- Main RAM address $1000-$13FF (1Kb) - RAMa
- Main RAM address $1400-$17FF (1Kb) - RAMb
- Main RAM address $1800-$1BFF (1Kb) - RAMc
- Main RAM address $1C00-$1FFF (1Kb) - RAMd
On each 1Kb of RAM the upper and lower nibble of data is checked, followed by address and data lines. If the test fails on the nibble then data/address lines will not be tested and the code will then move onto the next block.
On each failure the status screen will also be updated with the chip number that is faulty.
Following these tests the CRC value is calculated for each ROM (Basic, Char, Kernal) and if a matching version is found the status page will be updated.
The code currently checks for
- 901460-02
- 901460-03
- 901486-01
- 901486-02
- 901486-06
- 901486-07
- JiffyDOS PAL KERNAL
- JiffyDOS NTSC KERNAL
INTERPRETING THE OUTPUT
EXAMPLE 1
When testing the main RAM, its broken down into 4 tests
- Upper nibble
- Lower nibble
- Address lines
- Data lines
EXAMPLE 2
When testing the RAMa / RAMb / RAMc / RAMd
- Upper nibble from RAMa (1000-$13FF) passes
- Lower nibble from RAMa (1000-$13FF) fails with chip reference shown (UD3 fail)
- ROM versions are calculated with CRC and shown
EXAMPLE 3
When testing the RAMa / RAMb / RAMc / RAMd
- Upper nibble from RAMa (1000-$13FF) passes
- Lower nibble from RAMa (1000-$13FF) fails with chip reference shown (UD3 fail)
- Upper nibble from RAMc (1800-$1BFF) fails with chip reference shown (UD5 fail)
- Lower nibble from RAMc (1800-$1BFF) fails with chip reference shown (UE5 fail)
