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Ultra Rare Working UK101 computer (1980) with various expansion eproms.
I have for sale my working UK101 computer which I personally built around 1980 and it even used to help me past my 'O' Level and A-Level computer science subjects at that time :-). I actually visited the Compukit Store in New Barnet, London to purchase the UK101 kit and also purchased an additional purpose designed case for it. It has 8K Microsoft BASIC enhanced by various EPROMS as explained later and the RAM was expanded on board from 4K to 8K on board using 0.5K byte 2114 static RAM chips. This could relatively easily be expanded today to 40K just by using the addition of a single 32K STATIC RAM chip (unheard of at the time as 2K was largest single Static RAM chip available then) on a self made external board. The original UK101 KIT/Instruction Manual is included but is in a used condition. An external regulated 5 volt 4 amp power supply is included with a a suitable connector to plug into the back of the case. I would recommend an On/Off switch is added to the case which would be extremely easy to do. Please Note: Due to the age of this item I would prefer it to be collected where I can show it working. I am happy to post it and will package it well but I cannot guarantee it will work on arrival and will NOT accept any Refunds or Returns on it. I have only tested the computer by switching it on and running a BASIC program as showed in the Photos. I have not checked that all the enhanced EPROMS work although the BASIC 4 and 5 appear to be and I have no reason to expect the others not too. I have not tested the standard or High Speed Cassette Interface. ALSO a manual for BASIC X is shown in the photos but this manual and the EPROM are NOT included in the Sale/Auction. Auction/Sale Details: I will only accept PAYPAL for payment and will only deliver to addresses in the United Kingdom. Payment must be made within 48 hours of winning/purchasing the item and I will endeavour to post it within 2 working days after receipt of payment. Any questions at all, please ASK. Happy Bidding. Various Enhancements were implemented to the UK101 as follows: 32 line Screen Modification: It has the common modification to double the screen display to 48 characters by 32 lines and I purchased has the enhanced CEGMON monitor EPROM which was designed for this 32 line display. The original instructions for carrying out the screen modification are included and so is the original manual for the CEGMON monitor. CPU "Clocked" Switch: There is a micro switch on the back of the case which enables you to select either the 1 mhz (standard) or 2 mhz (clocked) CPU timing speed. The processor on the board is a 6502A which supports up to a 2 mhz clock speed and the RAM chips have a faster enough write time to work with this modification. However the switch must only be used when the two RESET buttons are used and a warm start carried out. Otherwise corruption to your BASIC / ASSEMBLER program could occur - worse still it could hang and you need to carry out a cold start losing your program. High Speed Cassette Interface: The original UK101 is supplied with a Cassette Interface which only works at 300 board but I modified it to work with 600 baud (common on board wiring modification). However I installed an external board which allowed the Cassette interface to work at various speeds up to 4800 baud which was very fast in those days. For 4800 baud it required an good tape recorder and high quality tapes but I imagine it should work really well with a modern digital recorder. Original instruction sheets are included. Additional EPROMS As can be seen from the photos, I installed a small extension ROM/EPROM board bought from Premier Publications (key supplier of hardware and software for the UK101 at that time). The original installation instructions are included. This board enabled me to relocate three of the 2K BASIC ROMS from the main board onto it and use the "freed up" slots on the main board for additional EPROMS with enhanced functions. The EPROMS were all purchased from Premier Publications (still with the original manuals) and are as listed follows: BASIC 4: Original ROM was also replaced with an enhanced version which gave options to save/reload files to tape by name which was really useful because I implemented a new High Speed Cassette Interface which could work upto 4800 baud (& various speeds in between) - alot faster that the standard 300 baud! Original instruction sheet included. BASIC 5: Additional EPROM which gave the following features: Graphics Commands: SCR, SET, TEST VLIN, HLIN, BLK, Formatting Text: PRINT USING command Monitor Commands: WI, CWI, PUTAT and INAT for CEGMON Screen windows General commands: &GO, &GO$, GET, GT, GS, RD Original Manual is included TOOLKIT II: Additional EPROM gave the following Features: New Commands: MC, VIEW, TRACE(TRON, TROFF) AUTO xx/yy, DUPL xx/yy, LIST xx-yy/zz, DELETE xx-yy, RENUM xx/yy, FIND xx-yy/string, REPL xx-yy/OLD$/NEW$ plus a List Line on Error Function ready for Edit function. Original Manual is included FULL 6502 ASSEMBLER/DISASSEMBLER: This ENCODER EPROM is a full feature 6502 assembler/disassembler supporting full mnemonics, labels, hex, dec, binary and ASCII input etc. As it operates from BASIC workspace the other utility EPROMS such as TOOLKIT II can be used in conjunction with it to provide sophisticated FIND, AUTO, REPLACE and other functions. It also ties in directly with the CEGMON full-screen editor. Original Manual is included |