A317 $20.00
RAM 23
Technical Manual
STATIC MEMORY 128K x 8 / 64K x 16
or
64K x 8 / 32K x 16
RAM 23 TECHNICAL MANUAL Copyright 1984 CompuPro Hayward, CA 94545
First Edition: August 1984 Document # 12058
File Name: RAM23.MAN Board No. 235
RAM 23 is a trademark of CompuPro.
DISCLAIMER - CompuPro makes no representations or warranties with respect to the contents hereof and ·specifically disclaims any implied warranties of merchantability or fitness for any particular purpose.
Further, CompuPro reserves the right to revise this publication and to make any changes from time to time in the content hereof without obligation of CompuPro to notify any person of such revision or changes.
All rights reserved. No part of this publication may be reproduced or transmitted in any form, or by any means, without the written permission of CompuPro. Printed and assembled in the United States of America.
CONTENTS
About RAM 23 • Technical overview
How to configure the RAM 23 for your system Switch settings for S1 - address selection • Theory of operation
Locating RAM lCs by address and bit Logic diagram
Parts list • •
Component layout • • • •
Customer service/limited warranty information
• 1 1
• 2
• 2
• 3 3
• 4-9·
• 10 11
• 12
RAM 23 TECHNICAL MANUAL
ABOUT RAH 23
The RAM 23 from CompuPro represents one of the most advanced RAM boards ever produced for the IEEE 696/5-100 Bus. By combining state-of-the-art static CMOS RAM technology with CompuPro-s design excellence the RAM 23 offers the most versatile, efficient and reliable performance available today. The board works as "byte-wide" memory in 8-bit systems and automatically switches to "word-wide" mode for today"'s newer 16-bit systems. It is available in two versions, 64K or 128L
TECHRICAL OVERVIEW
The RAM 23 uses 16 high performance: 8K X 8 CMOS RAM chips to provide a total of 128K bytes or 64K words of.storage. It is also available in a version with eight high performance 8K X 8 CMOS RAM chips to provide a total of 64K bytes or 32K words of storage. The RAM 23 is addressable on any 128K byte boundary for the 128K byte version, or any 64K byte boundary for the 64K byte version in the 16 megabyte addres~ space specified by the IEEE 696 standard.
The RAM 23 also dynamically switches between "byte-wide" or "word-wide"
modes per the state of the sXTRQ* signal on the 5-100 bus (seethe Theory of Operation section for a complete discussion of how this protocol works).
CompuPro"'s RAM 23 has speed to spare when running our CPU 286/287, 68K, 8086, 8088, CPU-Z, and CPU 32016 boards at even their highest speeds.
The RAM 23 will also work with 8086/88 type CPUs at 12 MHz when these chips become available. It also handles high-speed DMA flawlessly, a feature few memory boards can boast.
To reduce the number of support ICs' required to pack all this performance and capacity onto a standard height 5-100 board, two PAL (programmable-array-logic) elements are used. The PALs select the proper memory chips and control the complicated data bus switching scheme required to mix 8- and 16-bit operations. . We also use a high-quality double-sided circuit board design that has a full solder-mask and legend. Sockets are provided for all ICs for ease of mainte~ance. All edge connector contacts' are gold on a nickel substrate to insure long and relia~le operation.
1
HOW TO CONFIGURE THE RAM 23 FOR YOUR SYSTEM
The RAM 23 requires only that the starting address of the board be set using switch Sl. All other features such as PHANTOM and byte (8 bit)/word (16 bit) transfers are handled automatically by onboard logic.
This board responds to the upper eight address lines (A16-23) as provided for by the IEEE 696/S-100 standard.
The starting address of the board is selected by setting paddles 1-8 of dip-swi tch Sl for a RAM 23 wi th 64K bytes and paddles 1-7 for a board with 128K bytes. Sl is located near the bottom left corner of the board. The address is set in a binary fashion with each paddle of Sl representing an address bit. An "ON" paddle represents a binary "zero"
and an "OFF" paddle represents a binary "one". The paddle to address bit relationship is shown in the following table:
SWITCH SETTINGS FOR Sl - ADDRESS SELECTION
ADDRESS BIT PADDLE NUMBER A23
· .. · · · ·
1A22
· · · · · · · ·
2A21
· · · ·
3 ON=
0A20
· · · ·
4 OFF 1A19
· · · · ·
5A18
· · · ·
6A17 7
A16
· · · · · · · ·
8Paddle 8 has no effect on boards jumpered for 128K byte operation.
Paddle 8 must be set on RAM 23 boards made to run at 64K bytes.
EXAMPLE: If this is the first RAM board in your system and you want 128K starting at address OOOOOOH, set paddles 1 through 7 of Sl ON.
EXAMPLE: If this is the second 128K RAM board in your system and you want it addressed at 020000H, set paddles 1 through 6 ON and paddle 7 OFF.
EXAMPLE: If you want this board to reside at the top of the first megabyte of address space (i.e., starting address OEOOOOH), set paddles 1 through 4 ON and paddles 5 through 7 OFF. This would put the board at the highest TZ8K address which an 8086 ~an 8088 can directly address.
2
THEORY OF OPERATION
The RAM 23 is designed to work in 8- and I6-bit systems per the protocol established by the IEEE 696/8-100 standard. The DATA IN and DATA OUT buses operate as a bidirectional I6-bi;t data path when word transfers are performed. The two buses remain uni-directiorial during byte operations.
Here's how the protocol works: The bus master requests a 16-bit transfer by asserting sXTRQ*. If the slave (in this case the RAM 23) is capable of performing word transfers, it acknowledges this fact to the master by asserting SIXTN*. Sometimes, even a 16-bit master may only want to transfer one byte rather than a whole word. In this case, the master does not assert sXTRQ* but instead uses the data buses as an 8 bit master would, that is, data from the master would be transferred on the DO bus and data to the master would be transferred on the DI bus.
The RAM 23 handles this multiplexing of the data buses with two bi- directional bus buffers (UI0 and UII) and'one intermediate buffer (UI2).
This complicated algorithm is executed by PAL (programmable array logic) element U6. A second PAL (U7) acts as the array decoder along with U4.
The RAM is configured as two arrays of 64K by 8 bits. The bit/address decode scheme is covered in the next section. The decoder PAL only generates select signals, which enable the RAM chips only during memory reference operations. This feature, coupled with the use of RAM chips which power down when not selected makes the RAM 23 consume less power than most dynamic RAM designs while providing the speed of operation ~nd
reliability that only static RAM delivers.
The base address of the .. board is set wi th dip-s wi tch S 1. Oc tal comparator (U3) generates signal ASEL* when the address present on bus lines A16 through A23 matches that set in 81-1 through 81-8. AI6 has no effect if the board is jumpered for I28K byte operation.
ESXT* is the signal generate~ in the PAL (U6) which causes the RAM 23 to ack'nowledge requests for word transfers when the board is selec ted.
Transistor QI p~ovides the open collector output required to drive bus signal SXTN* (line 60).
Parallel decoding speeds up the response time. An onboard generated early wri te signal (OBG) is used to take advantage of the speed of the 8-100 bus. The write signal is started early and stretched out as long as possible.
LOCATING RAM ICs BY ADDRESS AND BYTE
The COMPONENT LAYOUT in this manual may be used as a map to locate RAM ICs' by address and byte. Each RAM chip is identified by address and' high or low byte position as written in each RAM location~
NOTE: The dotted line around the eight center most RAM chips on the COMPONENT LAYOUT indicates the RAM chips present in a 64K board.
3
LOGIC DIAGRAM
1 of 6
AIlE> I B > 2 • MA~
4· MAl
A3
In> 9Gl>B
• MA2A4
W> SGl>6
~ MA3A6 MA5
A7 MA6
A8
IS> 3~
• MA7A91B>
S~
• MA8Ala
Ei> 13~2
• MA9 AllEi> 11~O
• MA 1 aA12 ~
1~
U9 • MA 11A13 MA12
A5
• MA4
- -
RAM 23 235A
CompuPro ©1984
4
A23 3
A22 17
5 U3
A21 15 25L~
2_521 A20
A19 7
A18 A17
3 9 11
--
ASEL*64 K 128K A16iD>
I
1
sXTRQ*
s MEr~R
PHANT*
sHO*
sOUT A15 A'IJ
Is rCA
- -
A16S5 3 7 9
11 128l</
~"---I P
W2
3 7 81 2
- -
J1
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5
S1
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RAM 23 235A
2 of 6
CompuPro ©1984
PHANT*
U6 18 sXTRQ*
pOBIN PN236 16
s MEr~R 14
sWO* 17
sOUT 19
A~ 15
12
1 NC
9 13
ASEL*
--
ESXT*
4 pWR*
t1W R I T E 6 8 > - - - '
6
EN 00*
ENOI*
ENX*
ESXT*
M Er~ R*
OBG
SXTN*
W*
RAM 23 235A
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CompuPro ©1984
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43 9 9 42 41 94 9 ENOl
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90 40 39 38 89 88 35 36 EN DO
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7 13
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14 15 17 11 16 18 12 13
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+ Cl 11
3 5 6
17
19
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M M
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4 of 6
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DB3 DB2
...
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MDA 7
MDA6 MDA5
t1DA4
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MDA 1
MDA0
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RAM 23 235A
CompuPro ©1984
5 of 6
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8
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r~OA6 , ... 18 06 r·10A 5 ... 17
, 05
MOA4 ... 16 04 M Et10 R Y .
... ARRAY
t·1 OA 3
15 A
, 03
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t~OA2 ... ... 13 02 MOAl ., ... 12 01 t·1 OA 0 ... 11
, DO
R/W* OE
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MEt·1R* :
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120
126r~OB 7 19 C51 C52
... 07
,
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..
... 18 06 HOB5..
, 17 05MOB4
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MOB3 15 B
... 03
,
t·1 DB 2 ... ... 13 02 MOB1 .... , 12 01 MOBO , ... 11 DO
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~ )W* ~
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9
18
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r·1A5~ MA7
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RAM 23 235A
CompuPro ©1984
PARTS LIST
SEMICONDUCTORS
QTY Description 16 6264p-12
8 6264P-12
1 25LS2521
2 74F02
2 74LS04
3 74LS245
1 CompuPro 11236 1 CompuPro 11237 1 CompuPro 11238
2 7805
1 MPS3646
CAPACITORS
26 Bypass Caps 1 68 pF silver
Mica
2 1.5 uF 6 volt (min. )
2 1.5 uF 10 volt (min. )
RESISTORS
1 SKI Ohm 1/4 W 5%
1 1K5 Ohm 1/4 W 5%
2 SKI SIP SOCKETS
4 14 pin 6 20 pin 16 28 pin MISC. HARDWARE
2 Large Heatsinks 2 6-32 panhead, 5/16"
2 1/6 lockwasher 2 6-32 1/4" nut
Location
U13 thru U28 (128K bytes version)
U15 thru U18, U23thru U26 (64K bytes version)
U3 U4, US U8, U9
U10, U11, U12
U6 (Programmable Logic Array, PAL) U7 (PAL - 128K version)
U7 (PAL - 64K version) U1, U2 (5 Volt regtilator) Q1
Location unmarked C5
C1, C3 C2, C4 Location R1
R2
SRI, SR2 Location U4, US, U8, U9
U3, U6, U7, U10, U11, U12 U13 thru U28
Location U1, U2 Ul, U2 Ul, U2 Ul, -U2 1 8 position dip switch SI
2 Card Extractors Upper corners 2x3 Double row pins Jl
2 Low profile shunts Jl
10
23
COMPONENT LAYOUT
r---"
I I
I I
I I
____ .J
First 64K Bytes
~
,; . - 'LIMITED WARRANTY· _.
COMPUPRO warrants this computer product to be in good working order for a period of one (1) year, (two [2] years CSC and six [6] months for disk drives) from the date of purchase by the original end user. Should this product fail to be in good working order at any time during this warranty period, COMPUPRO will, at its option, repair or replace the product at no additional charge except as set forth below. Repair parts and replacement products will be furnished on an exchange basis and will be either reconditioned or new. All replaced parts and products become the property of COMPUPRO. This limited warranty does not include service to repair damage to the product resulting from accident, disaster, misuse, abuse, or unauthorized modification of the product.
If you need assistance, or suspect an equipment failure, always contact your COMPUPRO System Center or dealer first. COMPUPRO System Center technicians are f?ctory trained to provide prompt diagnosis and repair of equipment failures. If you prefer, or if you are not satisfied by the actions taken by your System Center/dealer, you may return the product to COMPUPRO for warranty service. Please call COMPUPRO at (415) 786-0909 to obtain a Return Material Authorization (RMA) number, or, write to COMPUPRO at 3481 Arden Road, Hayward, California 94545, Attn.: RMA. Be sure to include a copy of the original bill of sale to establish purchase date.
If the product is delivered by mail or common carrier, you agree to insure the product or assume the risk of loss or damage in transit, to prepay shipping charges to the warranty service location (System Center or COMPUPRO) and to use the original shipping container or equivalent. Contact your COMPUPRO System Center/dealer or write to COMPUPRO at the above address for further information.
ALL EXPRESS AND IMPLIED WARRANTIES FOR THIS PRODUCT, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE LIMITED IN DURATION TO A PERIOD OF ONE (1) YEAR FROM THE DATE OF PURCHASE, AND NO WARRANTIES, WHETHER EXPRESS OR IMPLIED, WILL APPLY AFTER THIS PERIOD. SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG AN IMPLIED WARRANTY LASTS, SO THE ABOVE LIMITATIONS MAY NOT APPLY TO YOU.
IF THIS PRODUCT IS NOT IN GOOD WORKING ORDER AS WARRANTED ABOVE, YOUR SOLE REMEDY SHALL BE REPAIR OR REPLACEMENT AS PROVIDED ABOVE. IN NO EVENT WILL COMPUPRO BE LIABLE TO YOU FOR ANY DAMAGES, INCLUDING ANY LOST PROFITS, LOST SAVINGS OR OTHER INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF OR INABILITY TO USE SUCH PRODUCT, EVEN IF COMPUPRO OR A COMPUPRO FULL SERVICE SYSTEM CENTER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY.
SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES FOR CONSUMER PRODUCTS, SO THE ABOVE LIMITATIONS OR EXCLUSIONS MAY NOT APPLY TO YOU.
THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE OTHER RIGHTS WHICH MAY VARY FROM STATE TO STATE.
COMPUPRO 3481 Arden Road Hayward, CA 94545
(415) 786-0909
Note: This warranty supersedes all previous warranties, and all other warranties are now obsolete.
#17806 Revised 384
12
GmpuPro@
12058/1 3056 Breakwater Court; Hayward. CA 94545 (415) 786-0909 4241000A
