Minter
Member
Hi everybody!
I'm trying to repair a memory expansión card for MMU CPU slot.
All CIs was changed. 74LS393, 74HCT245, 74HCT244 and 74HCT158, but nothing happened.
During the startup, keeps the black (dark) screen and ... no more (i dont remember what happened with the LED
, but i think nothing)
I'm waiting for Green screen to be sure if it had a DRAM problem.
Two possibilities:
- I have the CPU damage. (without the expansion card, the computer Works fine but 512kb chip RAM
)
- The PALs of the expansión card (380763-01, 380764-01 or 380765-01) are broken.
Replace the CPU is easy, but not with the memory expansion PALs. I dont have a spares.
Someone had the PAL ecuations to generate a new ones?
The PALs are:
380763-01 PAL RAM DECODER - PAL16L8
380764-01 PAL RAM CONTROL I - PAL16L8
380765-01 PAL RAM CONTROL II - PAL16R4
Thx!!!
I'm trying to repair a memory expansión card for MMU CPU slot.
All CIs was changed. 74LS393, 74HCT245, 74HCT244 and 74HCT158, but nothing happened.
During the startup, keeps the black (dark) screen and ... no more (i dont remember what happened with the LED
, but i think nothing)I'm waiting for Green screen to be sure if it had a DRAM problem.
Two possibilities:
- I have the CPU damage. (without the expansion card, the computer Works fine but 512kb chip RAM
)- The PALs of the expansión card (380763-01, 380764-01 or 380765-01) are broken.
Replace the CPU is easy, but not with the memory expansion PALs. I dont have a spares.
Someone had the PAL ecuations to generate a new ones?
The PALs are:
380763-01 PAL RAM DECODER - PAL16L8
380764-01 PAL RAM CONTROL I - PAL16L8
380765-01 PAL RAM CONTROL II - PAL16R4
Thx!!!
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