The Z88 has 32K of internal RAM. This is not enough memory for every day use.

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Memory prices have fallen since then so this is more attractive now to go for the largest card available.

1M RAM

Picture	Device	Operating	Standby
Image ModifiedImage Modified	CYPRESS SEMICONDUCTOR - CY62158ELL-45ZSXI - SRAM, 8MBIT, PARALLEL, 45NS, 44TSOP This memory chip is being used in the Rakewell's Flash/RAM card successfully. TESTED OK  Datasheet	1.8 mA	2uA
Image ModifiedImage Modified	BSI (BRILLIANCE SEMICONDUCTOR) - BS62LV8001EIP55 - IC, SRAM 8M, 1024KX8, 2.4-5.5V, SMD This memory chip has been used in the Rakewell's Flash/RAM card successfully. TESTED OK  This part is no longer manufactured. Datasheet	10mA	3.5uA
Image ModifiedImage Modified	ALLIANCE MEMORY - AS6C8008-55ZIN - SRAM, 8MB, 2.7-5.5V, 1024KX8, TSOP44 TESTED FAILS

  

Image ModifiedImage Modified	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.

  

512K RAM

Image Modified	Amplia un cartucho de Z88 hasta 512Kbytes - 512Kb Cartridge for Z88
Image Modified	ALLIANCE MEMORY - AS6C4008-55SIN - SRAM, 4MB, 2.7V-5.5V, 512KX8, SOP32 Note: This has not been tested. It will probably fail.

Internal RAM (fitted on the Motherboard)

The internal 32K of RAM is not large enough. Upgrading this to 128K or 512K internally is possible, but the original 'built-in' OZ operating system did not use this correctly.

Cambridge Computer commissioned OZ 4.0 ROM and were planning to use this with the new User Guide v3 but only the User Guide was changed. The new ROM was made available to users through the Z88 User Group.

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Note: On this motherboard the RAM socket is a 24 pin which is big enough for 32K. Later versions had a 28 pin fitted.

512K RAM

Picture	Device	Operating	Standby
Image Modified	32K RAM Standard in Z88 NEC 42832 32k x 8 Pseudo Static RAM 150 mS Datasheet	1 W 200mA	2.8 mW 560uA
Image ModifiedImage Modified	HITACHI HM658512LP-12 4Mb PSRAM HM658512 (250mW active) TESTED OK by Benny 02 Feb 2016  This part is no longer manufactured.	75mA

 

	2mA
Image Modified

 

CYPRESS-SEMICONDUCTOR-CY62148ELL-55SXI-IC-SRAM-4MBIT-512KX8-5V SOIC32 Data Sheet This part is no longer manufactured.

 

20mA

 

	3.5uA
Image Modified	ALLIANCE MEMORY - AS6C4008-55PCN - SRAM, 4MB, 2.7V-5.5V, 512KX8, PDIP32

This has not been tested yet Datasheet

Successfully tested. Datasheet.	30mA	4uA
Image Modified	ALLIANCE MEMORY - AS6C4008-55SIN - SRAM, 4MB, 2.7V-5.5V, 512KX8, SOP32 This has not been tested yet.	30mA	4uA

128K RAM

Picture	Device	Operating	Standby
Image Modified	ALLIANCE MEMORY - AS6C1008-55PCN - SRAM, 1MB, 2.7V-5.5V, 128KX8, PDIP32 This has not been tested yet	10mA	1uA

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