Hardware / RAMpage AT (AST)

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Expand your DOS memory with EMS, XMS, HMA and UMB

A very good introduction to the subjects of "EMS, XMS, HMA and UMB" can be found in the documentation of "USE!UMBS" by Marco van Zwetselaar from 1991. Just take your time and read it, it's worth it!

The Rampage AT is a memory expansion adapter for the IBM PC/AT and 100% compatibles running at *6MHz. Memory can be expanded on this board from 512K to 2048K using industry standard 256K dynamic RAM chips with a minimum speed requirement of 120NS. Memory standards supported by the Rampage AT include conventional (base 640K), linear extended, LIM 3.2, LIM 4.0, and EEMS.
AST Part Number 202079-001 bulletin

With the RAMpage AT, you can fill conventional memory up to 640K, submit extended memory or expansion memory. You can do all three things at once or separately, as you need it in your system.

Rampage 286 (AST)
RAMpage AT (AST), version 202079-301A

RAM

The RAM chips used with the RAMpage AT board must be 12O-nanosecond access time or faster.
AST Part Number 202079-001 bulletin
Rampage 286 (AST)
RAMpage AT (AST), 512KB, 120ns RAM

My 286AT system configuration

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According to the AST technical bulletin 0191 this „6Mhz" version should not work with a „8MHz" IBM 5170 mainboard, but it does anyway by me!

Here is the memory map of my IBM 5170 with Hercules Graphics Card (HGC). You will notice that the E area (E000-EFFF) is unused and could actually be used. But it is unmappable; you can check with MANIFEST (MFT)! REMM.SYS cannot provide this area, because it could NOT be used on the original IBM AT and IBM XT/286, see minuszerodegrees.net / 5162 and minuszerodegrees.net / 5170 (U17 / U37).

The manual explicitly states that only the C000-E000 range can be used. The E area is not mappable by REMM.SYS because it was planned by IBM for future ROM expansion!

Strangely, you can put the EMS page frame on A000, although this is not possible according to the manual, see manual page E-8. But this only works with an MDA or HGC card!

Switches

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SWITCH BLOCK 1
(TEN POSITIONS; ON = TOWARD NUMBERS)

LINEAR
MEMORY SW1-1 SW1-2 SW1-3 SW1-4
------ ----- ----- ----- -----
128K   ON    ON    ON    ON (default)
256K   ON    ON    ON    OFF
384K   ON    ON    OFF   ON
512K   ON    ON    OFF   OFF (my setting)
640K   ON    OFF   ON    ON
...

BASE I/O ADDRESS
ADDRESS SW1-5 SW1-6 SW1-7 SW1-8
------- ----- ----- ----- -----
0208h   ON    ON    ON    ON
0218h   ON    ON    ON    OFF (default)
0258h   ON    OFF   ON    OFF
...

DUAL PAGE MODE
SW1-9   ON=ENABLED

SW1-10  OFF  (unused)

The above settings define how much of the memory on the Rampage will be used as conventional (base 640K) and/or extended linear memory. Any memory not used by these settings will be available as EMS expanded memory.

If the Rampage is to be used exclusively as EMS expanded memory, set the switches on Bank 2 (below) accordingly, and the above settings will be ignored.


SWITCH BLOCK 2
(EIGHT POSITIONS; ON = TOWARD NUMBERS)

START
ADDRESS SW1 SW2 SW3 SW4 SW5 SW6 SW7
------- --- --- --- --- --- --- ---  ---
0K      ON  ON  ON  ON  ON  ON  ON
128K    ON  ON  ON  ON  ON  ON  OFF
256K    ON  ON  ON  ON  ON  OFF ON
384K    ON  ON  ON  ON  ON  OFF OFF
512K    ON  ON  ON  ON  OFF ON  ON (my setting)
640K    ON  ON  ON  ON  OFF ON  OFF
...

Configuration

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To use the RAMpage AT properly for memory optimization, you need two more programs. One for the HMA and one the UMB management. For the HMA I use HIMEM.SYS for the UMB management I use QRAM.SYS from Quarterdeck.

Here is the Quarterdeck Manifest (MFT) file with all information.

Documents

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Downloads

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