The Sharp PC5000 is a portable MS-DOS compatible machine.
This means the hardware is not IBM-PC compatible, and it uses
a special version of MS-DOS. 2.00 in this case. In the early
days (1983) of the PC this was not uncommon. The screen is
640 x 80, giving it 80 characters wide by 8 lines.
Another feature is the OFF key. It will not switch off the computer, but is for a sleep mode (which must be supported by software). The OFF.COM program (part of the DOS) however always works.
|Side view||The internal memory is 128 KByte, which can be extended
with RAM cartridges like the CE-100M (64 KByte RAM) or CE-103M
(128 KByte RAM). The cartridge slots also accepted ROM
cartridges, like Extended Basic (64 KByte ROM) or EasyPac
(CE-116M), a software suite consisting of EasyWrite II,
EasyReport and EasyComm. The cartridges are places at slots at
the bottom of the PC-5000. They contain dynamic RAM, so are
The 128 KByte CE-103M can only be installed at slot 1. A 64 KByte will work in both slots, but when combined with a CE-103M in slot 1, will have the switches set on CS:2 and MAP:A and must be placed in slot 2. If two CE-100M modules are used, one must have MAP set to A, the other to B. The CE-103M doesn't have switches. The EasyPac ROM module wants slot 1, BASIC ROM can be in both.
|With disk unit||The Floppy Disk Unit contains both drives and disk controller board. The disk controller board contains a uP765 chip, the same as the IBM-PC. The system accepts standard 5 1/4 " 360 KByte MS-DOS floppies. The Drives are designated C: and D:, leaving A: for the Bubble Memory. Booting from the C: floppy is possible if no bubble is present.|
The bubble memory is one of the parts that make the PC-5000
special. Look here for more info on
bubble technology or see the Functional Description from the Intel
Component Data Catalog from 1981. Each bubble (adressed as
drive A:) seems to contain a read-only bootable MS-DOS and
128 KByte storage capacity. The build in CHKDSK reports:
257024 bytes total disk space 39936 bytes in 6 hidden files 93184 bytes in 6 user files 123904 bytes available on diskThe user files are:COMMAND.COM, MODE.COM, OFF.COM, CHKDSK.COM, EDLIN.COM and BASICEXE.EXE. These files cannot be deleted.
The bubble modules contain apart from the bubble itself some passive components a Hitachi HA16635 IC (30 pins SMD). This could contain the MSDOS, but then one would expect a copyright on the case. So probably the MS-DOS is build into the PC-5000, just as BASIC, but will only boot if a bubble or a bootable MS-DOS present.
If neither is the case, you get the built-in demo (BASIC is also an option, but depends on the BASIC module being installed). The blurb below is part of this demo.
The ROMs contain this fine marketing blurb, which I want to share:
Some info on the power supply: 15 V DC / 600 mA. Pin is minus, barrel plus.
Latest update: 2002-06-30