Ardent Tool of Capitalism

Bull Micral 500

rf7080a.exe Model 70/80 386 Reference Disk v1.12 (zipped image)
   Warning: The original Micral 500 refdisk is pure unobtainium. Use the PS/2 Model 70/80 refdisk to configure the system. It's not perfect (base memory not being reported correctly) but it works.

Paradise/WD VGA files (Metropoli BBS files, archived)

Specifications
Micral 500 Planar
Chipset
System Firmware
   ROM Images
Exhaust Fan Assembly
Speaker/Battery/LED Assembly
   Interconnect Board
   LED Board
   Battery Pack
   Speaker
Power Supply

Photos, ROM images, and other material provided by Stefan Lemanski.

Specifications (Type CPU1334)

CPU: i80386DX 20 MHz (PGA), optional math co-pro (PGA)
Memory: 8x 30-pin SIMM slot on the planar (industry standard?)
Bus: MCA, 1x 32-bit, 3x 16-bit (one w/ AVE, one internal)
Video: Paradise VGA (on-board), 256 KB video RAM
HDD: WD1007V-MC1 ESDI + Seagate ST1201E (200 MB)
FDD: 3.5" 1.44 MB (34-pin, Mitsubishi MF355C-213U)
I/O: PS/2 keyboard & mouse, 1x 25-pin serial, 1x parallel

The machine imitates the original PS/2 Model 80 with the 16 MHz Type 1 planar (ID FEFF, model F8, submodel 0).

Micral 500 Planar N290619000-08K, A-M-020078

P17 The second Molex connector is not populated and the +12 V pad is jumped by a thick bodge wire directly to the PSU edge connector. The original +12 V trace was probably too thin to satisfy the HDD/FDD current draw.

Z2 There's a small PCB under the math co-pro socket. It only contains a resistor network and two discrete resistors. (pullups or termination?)

P5 Internal 16-bit MCA slot. Comes with the WD1007V-MC1 ESDI controller pre-installed.

The rest of the board is covered with 74xx glue, a couple PLDs, and a bunch of passives.

Chipset

Developed by G-2 Inc., also sold as Headland GCK181.

Headland GCK181 Universal PS/2 Chip Set Datasheet
   GC181 - Bus Controller (page 3 physical)
   GC182 - Memory Controller (page 15 physical)
   GC183 - DMA Controller (page 27 physical)
   GC186 - Peripheral Controller (page 49 physical)

Semiconductor User Information Service Newsletters 1988-1989 (page 144 physical) says:
   "LSI Logic's affiliate, G-2, has entered into an agreement with Groupe Bull of France to manufacture an IBM PS/2 compatible chip set. The chip set includes the GC181 CPU bus controller, the GC182 memory controller, the GC183 DMA controller, the GC184 address-data buffer, and the GC186 peripheral controller. The 20-MHz chip set, which will be sampled in the third quarter of 1988, will be fabricated with a 1.5-micron (1.2-micron effective) CMOS process. (25 Jul 1988)"

System Firmware (POST & BIOS)

Firmware stored in EPROM.

ROM Images

All ROMs are AMD Am27C512-155DC, positions Z46/Z47 (even/odd).

S_802-06 / S_803-06 - BULL SYSTEM BIOS Version B1.1a (rev. 5, 09 Nov 1989)

Exhaust Fan Assembly

The construction of the fan assembly is similar to that of the Model 50. Plastic shroud with a fan and small PCB inside. The fan is held in place with a foam, no clips, no screws...

Fan Model

SANYO
BRUSHLESS DC Mini Ace 25
MODEL 109P0912M4021
DC 12 V 0.1 A
SANYO DENKI CO.,LTD.
MADE IN JAPAN

Dimensions: 92mm, 25mm thick

SAN ACE 92mm MINI ACE DC Fan Motors Datasheet

Fan PCB "VENTIL." 729059008-00A

The fan PCB has a provision for two passive components (resistor + thermistor?) but neither was populated on the only sample we have seen (possibly a crude temp control?).

Fan Connector Pinout

6-pin card-edge connector on the planar board.

Pin Signal Pin Signal 1 Ground 2 N/C 3 +12 V 4 N/C 5 +12 V 6 N/C

Speaker/Battery/LED Assembly

The assembly consists of the support frame, an interconnect PCB, an LED PCB, a speaker, and a battery.

The frame also doubles as an adapter card support.

Interconnect Board "C. INTERCONNEXION" 7290582008-01C

Edge Connector

12-pin card-edge connector on the planar board.

Pin Signal Pin Signal 1 N/C 2 Speaker Data 3 N/C 4 GND (Spkr./Batt.) (?) 5 "ST" Jumper (?) 6 Battery+ 7 Hard-Drive LED- 8 Hard-Drive LED+ 9 Power LED- 10 Power LED+ 11 N/C 12 N/C

P2 "LED" - LED Board Connector

P3 "H.P." - Speaker Connector

P4 "BAT" - Battery Connector

"ST" Jumper

Clear CMOS jumper?

LED Board "CARTE LEDS" 7290589008-00A

Contains the Power ("A/M") and Hard-Drive activity ("DISQUE") LEDs.
Plugs into the Interconnect Board.

Battery Pack

The battery pack consists of two Li-Ion 2.5 V non-rechargeable AA cells wired in series to give approx. 5 V total. The cells are stuffed in a box with a 4-pin header connector attached to it via a twisted pair wire.

The pack is wired to the Interconnect Board.

You probably won't be able to get a replacement battery pack, but you can open the original one and replace the cells. Alternatively, you can replace the entire thing with a battery holder or another battery with equivalent specs.

Warning: Never solder directly to a battery/cell. Either buy cells with contacts already attached, get a mini spot-welder, or use a battery holder. Excessive heat may damage the cell and lead to a fire or an explosion! You are doing this at your own risk.

Original Battery

Made by SAFT
Lithium, 5.2 V, 2.3 Ah
BULL 76957876 002

Speaker

Bukooo
66SP03
8 Ω 0.4 W

Plugs into the Interconnect Board.

Power Supply

Similar form factor as the Model 50/70 PSU, but bigger.

ASTEC Model No. BM135-3301

Input: 230 V AC, 1.8 A, 50/60 Hz

Output voltages:

Maximum continuous output power is 135 W.

The pinout is the same as for the Model 50/70 PSU, except for the "System Status" signal on pin 49 that is missing here (hard-drive activity LED on Models 50/70).