Mike Maginnis wrote: > On 22 Aug 2006 16:16:52 -0700, a2aviator@gmail.com wrote: > >> The answer is probably in the thread- but the thread isn't all showing >> for me right now... >> >> If the card is producing garbage on insertion and activation, it's >> either got bad logic in the simple circuit portion or it's got bad RAM >> in bank A. Within the first two ICs. The rest of it is non-existant >> until called apon. The four ICs in the middle are probably labeled >> "AE1", "AE2", etc. > > Four ICs in the middle (between the expansion headers, closest to the > keyboard end of the card) have nothing on them - closer examination > reveals that whatever was printed on them has been scraped off. > > The other four are: 74LS245N, 74LS08P, 74LS374P and 74F32N. > >> Somewhere I have some notes as to what those really are. They're just >> relabled 74xx series. Nothing on the card is special except the >> GAL/PAL. >> >> If simply swapping some RAM from elsewhere on the card into the A bank, >> or even within the A bank produces the same results then I'd be going >> to look at the simple circuit part of the card which is the 244/245/373 >> stuff along with the A bank of RAM. It's repairable. No question there. >> The PAL is not even needed for basic operation. It's a pretty >> straightforward card. >> > > Switching the DRAMs in the A bank didn't. This is sounding more and > more like a solder job, which is out of my skill set. > >> Some out there in the wild even have normally labeled ICs on those >> positions, so if everyone looks at their RAMWorks cards and notes what >> ICs are installed in the center area between the two expansion headers >> and make a note of what is in what position. They are labeled Ux, >> (example, U2, U3, U4) > > Mike Maginnis > maginnis@computist-project.net > > The Computist Project > http://computist-project.net This image might help you in figuring out which IC's you are looking at. It is a scan of my collection of Apple ][ Cards including the Ramworks III (Caution 1mb Jpeg's) http://www.syndicomm.com/~technerd/Apple_Scans/ http://www.syndicomm.com/~technerd/Apple_Scans/RamworksIIIF.jpg -- V/R Mark Frischknecht si vis pacem, para bellum http://www.appleiiguy.net Apple ][ Forever!
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