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 through it, it's worth it!
Rampage 286 Expanded Memory Card for the IBM Personal Computer AT and XT Model 286.User's manual, Title, 1986
The model Rampage 286 is the first version. The next version is the Rampage Plus 286, which is also intended for compatible 286 AT computers. But! Also the first version seems to run on compatible 286 AT computers. At least this is the case for me.
Rampage 286 is a flexible and powerful memory enhancement board, which represents a new generation of products to expand the available memory for your Personal Computer XT (PC XT) Model 286 or PC AT.User's manual, p. 1-1, 1986
With the Rampage 286, 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.
RAM
The RAM chips used with the Rampage 286 board must be 12O-nanosecond access time or faster (such as 100-nanosecond).User's manual, p. 1-3, 1986
If you look at the following picture, you will notice that only bank 0 has 100ns RAM chips. The other 3 banks are populated with 150ns RAM chips. But so far my system has worked. For this reason I switched off the turbo mode, i.e. the 286AT runs only at 6 MHz. I used the 150ns RAM chips because I had so many of them left.
At 6 or 8 MHz, it makes practically no difference whether you use 120 or 150ns of RAM. At 10 MHz and above, you must use at least 120ns of RAM, but 100ns is better.
Update 10.01.2021:
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What a fiddly job! I removed all 150ns DIL's today and replaced them with 100ns DIL's. The 100ns RAM's were in my Intel Above Board Plus, although they are not needed there at all. To be on the safe side, I tested all (3 x 2 x 9 = 54) DILs with my Polar D320 before installing them. You never know! Why did I do this? So that I can release the speed brake (6 MHz) again and use the full 12 MHz again. All 4 banks are now populated with 100ns DIL RAM's (4 x 2 x 9 = 72).
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My 286AT system configuration
- OS: .... MS-DOS 6.22
- MB: .... Unidentified 80286 VLSI
- TS: .... yes (12/6 MHz)
- MHz: ... 12 MHz
- WS: .... 0
- BIOS: .. AMI, Date 04/09/90, 2x type 27256
- RAM: ... 1 MB (DIL, 4x9 Siemens HYB41256-10
- EXP: ... 2 MB, Rampage 286
- CPU: ... Intel N80286-12, IIT 2C87-12
- VIDEO: . Hercules Graphics Card (GB102)
- NET: ... 3Com III 3C509B
- HDC/FDC: WD1006V-MM2 (WD37C65BJM)
- OPT: ... CompatiCard I, Rev. B, 1986
- HDD: ... Seagate ST225 (MFM)
- FDD: ... Mitsubishi M4854-342 (8")
- FDD: ... Mitsubishi M4855-112U (MOD, 5.25", only 720K)
- FDD: ... TEAC FD-55GFV, FD-55BR, FD-235HF
- CDR: ... MicroSolutions Backpack 162550 (2x)
Here is the memory map of my 286AT 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 (E000-EFFF) is not mappable by REMM.SYS because it was planned by IBM for future ROM expansion!
Switches
My settings: To use all of Rampage 286 memory as expanded memory (EMS) set SW2-1 through SW2-7 to OFF. SW1-1 through SW1-4 will then be ignored. I didn't set much more than that.
Configuration
To use the Rampage 286 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.
This is my CONFIG.SYS
Downloads
- Rampage 286: User's Manual 1986 with Addendum, (45 MByte)
- Rampage Plus 286: User's Manual 1988 with Addendum, (5 MByte)
- Settings for various AST cards: Settings (source unknown)
- Qurterdeck qram: User's Manual, (8 MByte)