DRAMS: Difference between revisions
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A<sub>4</sub><br> | A<sub>4</sub><br> | ||
A<sub>5</sub><br> | A<sub>5</sub><br> | ||
A<sub>7</sub><br> | |||
|} | |||
</tt> | |||
===4464=== | |||
64Kx4 bit DRAM chip | |||
4 of this IC make the 128K RAM of the [[ZX Spectrum +2A/2B, +3/3B]]. | |||
e.g:MICRON MT4067-15 | |||
Pinout: | |||
<tt> | |||
{| | |||
| style="text-align:right;" | | |||
{{overline|OE}}<br> | |||
DQ<sub>1</sub><br> | |||
DQ<sub>2</sub><br> | |||
{{overline|WE}}<br> | |||
{{overline|RAS}}<br> | |||
A<sub>6</sub><br> | |||
A<sub>5</sub><br> | |||
A<sub>4</sub><br> | |||
(+5V) V<sub>CC</sub> | |||
| style="border: 1px solid black" | | |||
1 ° 18<br> | |||
2 17<br> | |||
3 16<br> | |||
4 15<br> | |||
5 14<br> | |||
6 13<br> | |||
7 12<br> | |||
8 11<br> | |||
9 10<br> | |||
|| | |||
GND (0V)<br> | |||
DQ<sub>4</sub><br> | |||
{{overline|CAS}}<br> | |||
DQ<sub>3</sub><br> | |||
A<sub>0</sub><br> | |||
A<sub>1</sub><br> | |||
A<sub>2</sub><br> | |||
A<sub>3</sub><br> | |||
A<sub>7</sub><br> | A<sub>7</sub><br> | ||
|} | |} | ||
</tt> | </tt> |
Revision as of 19:31, 17 October 2016
DRAMS
Dynamic Random Access Memories used in ZX Sopectrum machines.
4116
16Kx1 bit DRAM chip
8 of this IC make the lower 16k part of the ZX Spectrum 16K/48K RAM.
e.g. NEC D416C-2
Pinout:
(-5V) VEE |
1 ° 16 |
GND (0V) |
4532
32Kx1 bit DRAM chip
The addressing logic uses 8 line (A0 to A7) for row address (RAS) and 7 line (A0 to A6) for column address (CAS). At CAS the A7 line has to be fixed at logic 0 or 1 depending on chip type.
8 of this IC make the upper 32k part of the ZX Spectrum 48K RAM.
e.g: TI TMS4532-20NL3 or OKI M3732-L TI TMS4532-20NL4 or OKI M3732-H
Pinout:
NC |
1 ° 16 |
GND (0V) |
A7 should set logical 0 at CAS for TI TMS4532-20NL3 and OKI M3732-L chips, and logical 1 for TI TMS4532-20NL4 and OKI M3732-H chips.
The A7 line is omitted for refresh address.
4164
64Kx1 bit DRAM chip
16 of this IC make the 128K RAM of the ZX Spectrum 128K and ZX Spectrum +2 (except ZX Spectrum +2A/2B).
e.g:NEC D4164C-3
Pinout:
NC |
1 ° 16 |
GND (0V) |
4464
64Kx4 bit DRAM chip
4 of this IC make the 128K RAM of the ZX Spectrum +2A/2B, +3/3B.
e.g:MICRON MT4067-15
Pinout:
OE |
1 ° 18 |
GND (0V) |