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Flakey HP 70: post modified as RAM Chip identified.
10-22-2015, 06:42 AM
Post: #3
RE: Flakey HP 70
According to this table the following chips are used on the HP-70:

Code:
part number   models                description    vendor(s)              notes
---------------------------------------------------------------------------------------------- 
1818-0078     35, 45, 55, 70, 80    CTC            AMI, Mostek MK6021P 
1818-0116     70                    ROM, 1024*10   AMI 
1818-0117     70                    ROM, 1024*10   AMI
1820-0993     45, 46, 70 , 81       RAM, 10*56     Mostek MK6036P         replaced by 1820-1393 
1820-1128     35, 45, 55, 70, 80    clock driver and reset, 16 pin DIP     
1820-1169     35, 45, 55, 70, 80    ARC            AMI, Mostek MK6020P

The RAM being the same on the HP-70 as the one on the HP-45 this can be an easy replacement source.
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Messages In This Thread
RE: Flakey HP 70 - Geoff Quickfall - 10-22-2015, 06:22 AM
RE: Flakey HP 70 - Didier Lachieze - 10-22-2015 06:42 AM
Damn it!!! - Geoff Quickfall - 11-08-2015, 01:48 AM



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