Difference between revisions of "DRAM chips"

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(Create with table of IC numbers vs bank and bits for Model A & B)
 
(Transpose table)
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|+ Model A/B  
 
|+ Model A/B  
 
|- style="text-align:center;vertical-align:top"
 
|- style="text-align:center;vertical-align:top"
!   !!       /CAS0      !!   /CAS1      
+
!!! D0  !! D1  !!  D2  !!  D3  !!  D4  !!  D5  !!  D6  !!  D7      
 +
|-
 +
! /CAS0
 +
|  IC61 || IC62 || IC63 || IC64 || IC65 || IC66 || IC67 || IC68
 
|- style="text-align:center;vertical-align:top"
 
|- style="text-align:center;vertical-align:top"
! D0
+
! /CAS1
| IC61 || IC53
+
| IC53 || IC54 || IC55 || IC56 || IC57 || IC58 || IC59 || IC60
|- style="text-align:center;vertical-align:top"
+
! D1
+
| IC62 || IC54
+
|- style="text-align:center;vertical-align:top"
+
! D2
+
| IC63 || IC55
+
|- style="text-align:center;vertical-align:top"
+
! D3
+
| IC64 || IC56
+
|- style="text-align:center;vertical-align:top"
+
! D4
+
| IC65 || IC57
+
|- style="text-align:center;vertical-align:top"
+
! D5
+
| IC66 || IC58
+
|- style="text-align:center;vertical-align:top"
+
! D6
+
| IC67 || IC59
+
|- style="text-align:center;vertical-align:top"
+
! D7
+
| IC68 || IC60
+
 
|}
 
|}
  
 
[[Category:Hardware]][[Category:Repair]]
 
[[Category:Hardware]][[Category:Repair]]

Revision as of 07:17, 22 February 2020

Model A/B

The Model B uses a total of sixteen 4816 DRAM chips to give it 32K of RAM. These chips are arranged in two banks of eight chips, /CAS0 and /CAS1. Each chip provides one bit of storage for 16,536 (16K) memory locations. The Model A uses only one bank, /CAS1. The use of either or both memory banks is controlled by selection jumper S25.

Errors in a particular bit will correspond to a specific IC:

Model A/B
D0 D1 D2 D3 D4 D5 D6 D7
/CAS0 IC61 IC62 IC63 IC64 IC65 IC66 IC67 IC68
/CAS1 IC53 IC54 IC55 IC56 IC57 IC58 IC59 IC60