Matrox MGA Impression/3/M & 3Z/M

@80EC.ADF Matrox MGA Video Adapter (V0.02)
@80EC.ADF Matrox MGA Video Adapter (V1.00)
   Less memory choices, no Zbuffer selection (permanently disabled) Windows 95 driver v2.01 (all Impression/Ultima) OS/2 driver v2.10 (all Impression/Ultima) Windows NT 3.51 driver v2.13 (all Impression/Ultima)
1571_230.exe Windows NT 4.0 driver v2.30 (readme) (all Impression/Ultima)
   Note: The files were not tested for compatibility with the MCA adapter yet!
rambios.sys Puts VGA BIOS in shadow RAM (more info HERE) Model 70 POST error 2401 after reset fix Finn Thogersen's VGADOC has some info on MGA's register set (matrox.txt)
impress.pdf MGA Impression Plus / Lite Owner's Manual (Jan 1995) (later PCI cards!)
Matrox MGA: The Fastest Windows Accelerators Around (PCMag article; 14 Sep 1993)

Matrox MGA Impression
Matrox MGA Ultima/Impression Variants
ADF Sections

Matrox MGA Impression "MGA-IMP/3/M/H", "506-01" [P]

A1 MGA L4A0755 IS-TITAN? (heatsink)
A4 Brooktree Bt485KPJ135 RAMDAC
A5 ICD2061A-1 Clock gen. (Cypress alt.)
A14 "806-01" PLCC-32 video BIOS?
A17 Xilinx XC3130-5 FPGA (MCA iface?)
J1 HDD15 video connector
M1,2,4,5,7-10 HM538123AJ-8 128Kx8 VRAM
M3,6,15,17 TMS55165DGH-80 256Kx16 VRAM
M11-14 Pads for ZIP-40 RAM (z-buffer)
M16 Pads for ZIP-28 RAM (?)
X1 14.3 MHz xtal (A5 clock gen.)

M11-14 Pads for ZIP-40 RAM (z-buffer) HM514260ZP (or AZ) 256Kx16 DRAM possibly? Populated on the 3Z/M only. Maybe some (early?) 3/M samples came with empty sockets?
M16 Pads for ZIP-28 RAM (?) HM514800ZP 512Kx8 DRAM possibly?

Note: Some of the reference designators are currently unconfirmed.

The adapter features a 32-bit MCA data bus and a 24-bit address bus (16 MB address space). Notice that there is only one edge connector "key", meaning the adapter won't fit into a 16-bit MCA slot.

Matrox MGA Ultima/Impression Variants

Ultima/1/AISA1 MB
Ultima/2/A (MGA-ULT/2/A/H or MGA-ULT/2/A)ISA2 MB
Ultima/2/V (MGA-VLB/2)VL-bus2 MB
Ultima/2/M (MGA-ULT/2/M/H)MCA2 MB
Impression/3/A (MGA-IMP/3/A/H)ISA3 MB
Impression/3/V (MGA-IMP/3/V/H)VL-bus3 MB
Impression/3/M (MGA-IMP/3/M/H)MCA3 MB
Impression/3Z/AISA3 MB2 MB
impression/3Z/MMCA3 MB2 MB
Impression Pro/4/V (MGA-PRO/4.5/V)VL-bus4.5 MB
Impression Pro/4Z/V (MGA-PRO/4.5Z/V)VL-bus4.5 MB4 MB

See VGA Legacy for the ISA and VL-bus adapters.


The RAMBIOS.SYS program puts the MGA's VGA BIOS in shadow RAM. For all AT, VL, and MCA MGA products, BIOS shadowing is MANDATORY for single-screen operation.

Since RAMBIOS takes up 32K bytes of memory, it may be desirable to load it "high" using a memory manager.

There are two alternatives to using RAMBIOS.SYS. The first method uses your computer system's ability to shadow a VGA BIOS. If your system supports this capability, it is usually accomplished through the system's configuration program. There are certain instances where this method may not work. The second method is to use a memory manager to shadow the BIOS.

If MGA is run in a dual-screen mode, the MGA's on-board VGA is disabled and video BIOS shadowing is therefore not required.

ADF Sections Matrox MGA Video Adapter (V0.02) & (V1.00)

Two versions of @80EC.ADF exist: "V0.02" and "V1.00". The significant difference is the presence of a Z-Buffer Item in ver. 0.02, while the ver. 1.00 has it permanently disabled under "Fixed Resources" (specifically pos[1] bit 5, 1: present, 0: absent).

Enable/Disable Adapter
   Enabled (normal use). Disabled if you are not using the adapter and enabling it causes a conflict with another device.
     <"Adapter Enabled">, Adapter Disabled

Enable/Disable Adapter
   There are 7 16K windows where you can map the MGA. Note: Use Map1 only if the on-board VGA is enabled.
     <"Map2 C8000"> (0c8000h-0cbfffh), Map3 CC000 (0cc000h-0cffffh), Map4 D0000 (0d0000h-0d3fffh), Map5 D4000 (0d4000h-0d7fffh), Map6 D8000 (0d8000h-0dbfffh), Map7 DC000 (0dc000h-0dffffh), Map1 AC000 (none)

Note: Ver. 1.00 removes Map1 (AC000), only 6 16k windows (duh!).

MGA on-board VGA
   Select 'VGA Enabled' if you want a single screen solution. This enables the VGA bios at C0000h (on the MGA adapter).
     <"VGA Enabled"> (0c0000h-0c7fffh), VGA Disabled (none)

Composite SYNC
   Select 'CSYNC Enabled' if you are using a composite sync monitor.
     <"CSYNC Disabled">, CSYNC Enabled

   'Zbuffer Present' if your MGA has it's ZIP memory installed on the sockets placed on the lower left area of the adapter. Default is 'Zbuffer Absent'.
     <"Zbuffer Absent">, Zbuffer Present

Note: Ver. 1.00 removes the "Zbuffer" item -AND- adds a "Fixed Resources" line to mask the Zbuffer enable bit to "Disable"

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Louis F. Ohland, Peter H. Wendt, David L. Beem, William R. Walsh, Tatsuo Sunagawa, Tomáš Slavotínek, Jim Shorney, Tim N. Clarke, Kevin Bowling, and many others.

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