Introduction

This section is for Z88 Users who have built or modified existing accessories to be used with the Z88.

Z88 Motherboard

Here is where all the parts are on the motherboard.

Flash EPROM

Rakewell will be selling their 1M / 512K Bare PCB (un-populated) if there is sufficient demand.

This allows the following cards to be built. 1M RAM, or 1M FLASH, or 512K FLASH, or 512K RAM or 512K RAM/FLASH card.

If you are interested in this, please contact Rakewell directly.

1M RAM

	The memory chip described in the article below is no longer available. A suitable replacement is listed below. Amplia un cartucho de Z88 hasta 512Kbytes - Convert 32K RAM card to 512K RAM Use the translate feature to read the article in English (or other language) 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 works with the Z88..
	ALLIANCE MEMORY - AS6C8008-55ZIN - SRAM, 8MB, 2.7-5.5V, 1024KX8, TSOP44 Note: This chip will be tested, results will follow.
	This memory chip is a 'drop-in' replacement for the BSI chip (see below). It currently fails in PipeDream OZ 4.2. More testing is required. LYONTEK - LY62W10248ML-55LLI - SRAM, 8M, 1MX8, 2.7-5.5V, 44TSOPII
	This memory chip has been used in the Rakewell's Flash/RAM card successfully. 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	A29040B Flash	BS62LV8001	AS6C8008	LY62W10248-55	CY62158ELL-45ZSXI

		Z80 4MHz	A29040B Flash	BS62LV8001	AS6C8008	LY62W10248-55	CY62158ELL-45ZSXI
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

The memory chip described in the article below is no longer available. A suitable replacement may be

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.

Amplia un cartucho de Z88 hasta 512Kbytes - Convert 32K RAM card to 512K RAM

Projects