The Z88 has 32K of internal RAM. This is not enough memory for every day use.
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 | Amplia un cartucho de Z88 hasta 512Kbytes - Convert 32K RAM card to 512K RAM The memory chip described in the article above is no longer available. Suitable replacement are listed below. Rakewell will be selling their Flash/RAM PCB. This may be used instead of modifying the original 32K PCB board. This would upgrade the card to 1M. |
 | CYPRESS SEMICONDUCTOR - CY62158ELL-45ZSXI - SRAM, 8MBIT, PARALLEL, 45NS, 44TSOP Note: This chip will be tested, results will follow. |
| ALLIANCE MEMORY - AS6C8008-55ZIN - SRAM, 8MB, 2.7-5.5V, 1024KX8, TSOP44 Note: This chip will be tested, results will follow. |
| LYONTEK - LY62W10248ML-55LLI - SRAM, 8M, 1MX8, 2.7-5.5V, 44TSOPII This memory chip is a 'drop-in' replacement for the BSI chip (see below). TESTED FAILS when loading a file in PipeDream. |
| This memory chip has been used in the Rakewell's Flash/RAM card successfully. TESTED OK This part is no longer manufactured. BSI (BRILLIANCE SEMICONDUCTOR) - BS62LV8001EIP55 - IC, SRAM 8M, 1024KX8, 2.4-5.5V, SMD |
Technical Spec of a Flash and RAM chips
| Z80 4MHz | AS6C8008 | ||||||
|---|---|---|---|---|---|---|---|
Supply Voltage Min | V | 2.4 | 2.7 | 2.7 | 4.5 | ||
| Supply Voltage Typ | V | - | 3.0 | 3.0 | 5.0 | ||
| Supply Voltage Max | V | 5.5 | 5.5 | 5.5 | 5.5 | ||
Input High Voltage | V | 2.2 to VCC | 0.7 x VCC min to VCC+0.3 | 2.2 to VCC+0.3 | 2.4 to VCC+0.3 | 2.4 to VCC+0.5 | 2.2 to VCC + 0.5 V |
Input Low Voltage | V | -0.3 to 0.8 | 0.5 to 0.8 | -0.5 to 0.8 | - 0.2 to 0.6 | - 0.2 to 0.6 | –0.5 to 0.8 |
Output High Voltage | V | 2.4 min | 0.85 x VCC | 2.4 min | 2.4 min | 2.4 min | |
Output Low Voltage | V | 0.4 max | 0.45 | 0.4 max | 0.4 max | 0.4 max | |
Standby Power | uA | 1 | 3.5 to 50 | 6 to 80 | 10 to 50 | 2 to 8 | |
| Power Consumption | mA | 20 - 40 | 39 | 60 | 30 to 60 | 1.8 to 3 | |
VCC for Data Retention | V | 1.5 | 2.0 | 1.5 | 2.0 | ||
| Read Timings | |||||||
| Read Cycle Time tRC | ns | 55 min | 55 min | 55 min | 55 min | 45 min | |
| Address Access Time tAA | 55 min | 55 max | 55 max | 55 max | 45 max | ||
Chip Enable Access Time tACE | 55 min | 55 max | 55 max | 55 max | 45 max | ||
| Output Enable Access Time tOE | 30 max | 25 max | 30 max | 30 max | 22 max | ||
| Chip Enable to Output in Low-Z tCLZ | 18 min | 10 min | 10 min | 10 min | 5 min | ||
| Output Enable to Output in Low-Z tOLZ | 18 min | 10 min | 5 min | 5 min | 10 min | ||
| Chip Disable to Output in High-Z tCHZ | 30 max | 20 max | 20 max | 18 max | |||
Output Disable to Output in High-Z tOHZ | 25 max | 20 max | 20 max | 18 max | |||
Output Hold from Address Change tOH | 0 | 10 min | 10 min | 10 min | 10 min | ||
| Write Timings | |||||||
Write Cycle Time tWC | 55 min | 55 min | 55 min | 55 min | 45 min | ||
Address Valid to End of Write tAW | 40 min | 40 min | 50 min | 50 min | 35 min | ||
Chip Enable to End of Write tCW | 0 | 50 min | 50 min | 35 min | |||
Address Set-up Time tAS | 0 | 40 min | 0 | 0 | 35 min | ||
Write Pulse Width tWP | 20 min | 30 min | 45 min | 45 min | 35 min | ||
Write Recovery Time tWR | 0 | 0 | 0 | 0 | |||
Data to Write Time Overlap tDW | 25 min | 25 min | 25 min | 25 min | 25 min | ||
Data Hold from End of Write Time tDH | 0 | 0 | 0 | 0 | 0 | ||
Data Setup to Write End | 25 min | ||||||
Output Active from End of Write tOW | 5 min | 5 min | 5 min | ||||
Write to Output in High-Z tWHZ | 25 max | 20 max | 20 max | 10 max | |||
| THE Z80 CPU : TIMING |
512K RAM
| Amplia un cartucho de Z88 hasta 512Kbytes - Convert 32K RAM card to 512K RAM The memory chip described in the article above is no longer available. Suitable replacements are listed below. |
 | ALLIANCE MEMORY - AS6C4008-55SIN - SRAM, 4MB, 2.7V-5.5V, 512KX8, SOP32 Note: This has not been tested. Rakewell will be selling their Flash/RAM PCB. This may be used instead of modifying the original 32K PCB board. This would upgrade the card to 1M. |
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