Quote:
Originally Posted by SiriusHardware
One thing I notice is that the EPROMs all appear to have 16-bit hex checksums written on the labels, which will be helpful if you get to the point of needing to know if they are still OK.
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Well this is a good point, I now have managed to read both the BASIC and TRAP EPROMS using my knocked up PIC processor / Raspberry PI EPROM reader. This was simple given the 2764 EPROMS only needs a +5v power supply.
Thank God I wrote the Checksums on the EPROMs when I programmed them more than 30 years ago. These EPROMs are HN482764G with a 250ns access time looking at the data sheet from Hitachi there in no mention of the data life but they have a wide storage range from -65 to +125 C. When I read them with my PIC processor reader after slowing it down to deal with the access time I get the correct checksums for both the BASIC and the TRAP (Triton Resident Assembly Language Package). So I am confident the data I have from them is correct but neither work on the Triton emulator written by Robin Stuart. I know I modified the BASIC so it could be used with my floppy disk file system. but can not remember if I modified the TRAP.
Given it may be the only copy out there I will have some work to do to disassemble it and find out what the problem is.
But given I get the correct checksums on both EPROMs looks like Hitachi did a good job as they still work, be interesting to see how they preform in a real system at Tritons full clock speed.
Next Stage is to read the four 2708 EPROM's and use these with the emulator, I hope these are in as good shape as the HN482764G are. But now we have to deal with the multi rail power requirements of the 2708. I did see a post on here regarding 2708 EPROM Power Sequencing so this is of concern.