Sharp PC-4500 (4502)
Release date: October 1987
Processor: Nec V40 at 7.16 MHz or equivalent (compatible with i80188)
Memory: 256 KB or 640 KB RAM expandable to 1.6 MB Including 1 MB of EMS memory
Display: CGA compatible monochrome LCD display (Backlit on models 4502 and 4521)
Storage: 1 or 2 floppy drives 3 "1/2 of 720 KB
1200 baud modem and optional external CGA
Software: Ms-Dos 3.2 Sharp
Particularity: Announced at Comdex Spring 1987 and marketed from October of the same year, this entry-level PC compatible PC is sold at a rather competitive price. The compatibility is good but the performances are not extraordinary. Note that it requires a version of Ms-Dos of origin Sharp to start.
3 versions ever existed:
PC-4501, 256 KB with 1 drive, LCD not backlit
PC-4502, 256 or 640 KB with 2 drives
PC-4521, 640 KB with 20 MB hard drive
My machine is a PC-4502, 2 Floppy disks, no HDD, back-lit display.
I got this machine 2 weeks back of the internet from a guy who said that it does not know if the machine is in working condition.
I am not very happy that I did not make any pictures how the machine looked when I got it but I can rate it a 5 out of 10.... and I will show you why.
1) The DC IN connector and wiring is missing.
2) The DC POWER BUTTON is missing.
3) The Floppy drives power connectors are missing. Power cables from the Power Supply to the motherboard are damaged and a few blown capacitors.
4) Missing bolts and screws
5) Cracked case
6) No AC Adapter
1) The DC IN connector and wiring is missing
|Thin plastic square with a hole for the DC IN Connector|
|Bringing the base at the right size so the DC connector will perfectly fit the hole|
|DC Connector - Not Original one|
|DC CONNECTOR in place|
2) The DC POWER BUTTON is missing
Lucky me I found this YouTube video of the inside of a PC-4521 machine....
So as you can see on the video the Power Button is similar with what you will find in an old laser pointer. And ...I still have some laser pointers in a shoe box in my storage.
And this is the Output of 20 minutes of hard work :)
3) The Floppy drives power connectors are missing. Power cables from the Power Supply to the motherboard are damaged and a few blown capacitors
|Replaced marked in RED capacitors. It seems the power supply did not start because of those.|
|New wiring for the Floppy Disk units.|
NOW WE CAN FINALLY TEST THE UNIT!
|1 out of 2 Drives are only present. Date is 10 of September 1987|
The weird thing is that the Keyboard is PASSED as test but no keyboard is attached at this moment...
There are some jumpers on this machine and I found some info on some forums... I really hope I can get the second FDD working so I can put MS-DOS 3.2 on 1 drive and some CGA apps on the other :)
"Here are the settings my PC4500 came with on the DIP switch bank on the bottom of the unit:
I would guess that one of these switches defines the presence of the second floppy drive and perhaps the presence of a full 640K memory card (I have both in this machine)."
The settings above suggest 640k memory and 2 FDD installed.