Nice to read and see all this Thank you everyone! The Pinitech adapter brings my test ROM to a higher level. Looks nice and no more messing around with wires, bending pins and a seperate LED.
Thank you for the video Chris. It nicely shows the behaviour of my latest test ROM.
When programming this test ROM -it was the first one I did- I had a few things in mind. Testing the memories over their entire range and a proper "missing addresslines" detection. It is easy to fool Leon's test ROM. Lift an addressline pin from one of the memories and you will see the test will pass. I also coded a feature to verify if the selection circuitry for the RIOT's is working properly. In theory, if there is something wrong there, we could be testing the same RIOT 3 times or 2 in the same time in stead of all 3 each.
I wanted to make a unique blinking pattern at the LED for each test. For example, when seeing 3 short flashes -> the display RIOT tested succesfully. Chris his video shows the blinking after the memory tests is always preceded by a shorter faint flash. This is caused by writing and reading the memories over their entire range. This affects addressline a6 to which the LED is connected. (In other test ROM's I programmed I used addressline a8 to connect the diagnostics LED but I wanted to be compatible with Leon for this one).
I also changed the output tests for the RIOT's. Leon programmed all RIOT I/O ports to be outputs. However, by Gottlieb's design, some are intended to be inputs: for reading the switch matrix and the slam switch input. My test ROM tests these as actually being inputs. You can use dipswitch bank 1-8 to "feed" the input port at switch matrix RIOT U4. The results are copied to the switchmatrix output port. If input PA2 is inactive, output PB2 will be inactive "0" too. When PA2 is active, output PB2 will "blink" with the same frequency as the LED at the pinitech adapter.
I also programmed an extended test ROM to be inserted in the gamerom socket (for system 80b: PROM2 socket). This one is not mandatory to use. If not inserted, the tests will be simply skipped by the main test ROM and it will proceed with the I/O tests. If inserted, the extended test ROM will provide you the following:
- communication test between gamerom socket (sys80B: PROM2 socket) and CPU
- Timer IRQ tests for all 3 RIOT's.
Earlier system 80 boards -like Spiderman, Panthera, ....- using 2 masked gamerom's need to be modfied first for using a single 2716 gamerom before you can use the extended 2716 test ROM.
For the last system 80B games which use a 2732 PROM2 (Excalibur, Big House, Hot Shots, Bad Girls, Bone Busters) I coded a 2732 version for this extended test ROM.