voidstar’s IBM PC 5150

Before either the IBM PC AT or IBM PC XT there was the IBM PC.

This article is to focus on aspects of my IBM PC 5150 setup. My more complete 5150 description is here.

First, a brief summary of the IBM PC line:

5100September 1975: 5″ 64×16 text CRT, 55lbs “portable”, ~$15k retail
5110January 1978 to March 1982 (added IEEE-488 port)
51201980: $13k, similar to a TRS-80 Model 2 that cost ~$3000
5322July 1981: Datamaster, ~$9k retail
5150 August 1981: five expansion slots, 63W PSU (~$1500 retail)

Early 5150 were Type-A; then around 1984 a Type-B 5150 was sold with slight cosmetic changes on the power supply, newer BIOS as standard, and mainboard could support up to 256KB instead of 64KB (see here)
5160 XTMarch 1983: 8 slots, 10MB HDD, no cassette port, 130W
5162Shipped with 6MHz ‘286, 156W PSU
5170 ATAugust 1984: ‘286 processor; 16-bit ISA BUS

The Apple Macintosh (1984) and Commodore Amiga (1985) were released around this time.
IBM PCjr (1984-1985) vs. Tandy 1000-series (1984-1993)
[ these were still 8088 based systems; IBM botched the PCjr but the Tandy version was essentially what the PCjr should have been ]
The IBM PC line ended in 1987, replaced by IBM PS/2 (featuring MDA bus to replace ISA {precursor to PCI-bus}, VGA standard, 1.44mb floppy, 72-pin SIMM, ‘386 models, etc.).

Here are notes about my particular IBM PC 5150:

  • Intel 8088 processor
  • 256KB RAM (all on the mainboard)
  • 63.5W Power Supply
  • 2x360KB Double Density 5.25″ floppy drives
  • Barcode sticker at back right corner: “S/N 08586235150″ (this same code “858623” is etched into the bottom of the case)
  • Type-F IBM Keyboard

Expansion cards (stock):

  • Serial+Parallel output
  • MDA+CGA video card output (separate 9-pin output, plus Composite output, plus parallel port output)
  • Floppy disk drive controller

Expansion cards (extra optional):

  • Creative Labs Sound Blaster 2.0 CT1350B [ ISA ]
  • VGA video card output [ ISA ]
  • XT-IDE DELUXE w/ 128MB CompactFlash + MicroRAM Expansion
  • 3COM 3C509BTPO 10Base-T network card [ mTCP ] [ 3C509B-nestor ]

Supporting components:

  • MDA/CGA to VGA adapter (to be able to use LCD monitor instead of CRT)
  • HxC SD-card 3.5″ Floppy Drive emulator
  • TRS-80 CCR-81 cassette unit with data cable (excursion to examine if the IBM PC cassette port could actually be used)

BELOW: Samples images of 5150 booting, playing Sopwith, playing Lemmings, and playing Alley Cat. Running Lemmings demonstrates how the original 1981 system could be expanded and remain useful even 10 years later (Lemmings was released February 1991).

IBM PC 5150 booted with no floppy disks results in loading Cassette BASIC (C1.0).

MDA to VGA adapter is working.

C1.0 BASIC was provided by Microsoft for IBM. There was no native support in the ROM BASIC to access the disk drives. Technically you could POKE your own assembly to access the disk drives, but the convenience and speed of disk drives quickly became standard and made the cassette storage obsolete.

Original arrangement of expansion cards…

PC Speaker

There is a cloth-material label attached to the speaker. It looks like paper-material but it definitely a woven fabric. It has the following printing upon it:

  • “PN 1124609”
  • “EC 238”
  • “FEBRUARY 1984”

Video Card (MDA+CGA)

This video card has the following etched labels:

  • Bottom front corner: “MADE IN USA (C) 1984”
  • Bottom back corner: “STB Systems Rev. A”, “S/N G1889”
  • Main Chip: “MC6845P JR58405”
  • Top rear: “APD.P.86 94V.0”
  • Bottom rear: “FRVOA”

The connect on the upper front appears to be a parallel port. I have the corresponding cable, which is a long cable that is connected to an expansion port plate.

Video Card (VGA)

  • Oak Technology (per BIOS bootup display)

Serial + Parallel Ports

  • EV-170A
  • PWA-00158-00

Floppy Disk Controller (FDC)

  • 37-pin back plate
  • Edge connector for master/slave (up to 2x) floppy drives

Mainboard / Motherboard

Several chips have the AMD logo!

Mainboard dip switch settings. See here

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