Geoff Wearmouth
Press plastic for a living but love the touch of rubber. Assembler of Gosh Wonderful and Looking Glass ZX Spectrum ROMs.
- Steve Vickers interviewed about his time at Sinclair, saving ROM space on the ZX81 and the ZX Spectrum and the new venture the Jupiter Ace. youtube.com/watch?v=kgWj...
- Reposted by Geoff WearmouthIt is with great sadness that we share the news of the death of Prideaux Fellow David M. Webb MBE (1983, Mathematics), who passed away yesterday. David was a distinguished Exonian whose legacy will not be forgotten. 🔗 Read the Rector's tribute: ow.ly/hhMa50XWF52 #ExeterCollegeOxford
- Reposted by Geoff WearmouthHappy New Year! ✨ Looking back at 2025 — a great year at SC: • 25 new updates of ZXDB • 8 major releases of new website features and fixes • 2,200+ videos re-created from the lost RZXArchive YouTube channel 🚀 2026 - looking forward to service the ZX Spectrum community - and related machines 😘
- Reposted by Geoff WearmouthIntel announced the 8087 floating-point chip in 1980. Now I have a blog post that explains a small part of the microcode in this chip. www.righto.com/2025/12/8087...
- Did you know that the first instruction in the ZX Spectrum ROM is DI - Disable Interrupts. Quite a dramatic entrance. The DI instruction was not used in the ZX80 and ZX81. Here is my ZX80 assembly listing from 2002. I tried to use the Logan O’Hara labels when apt. web.archive.org/web/20150501...
- How to set your ZX Spectrum to 10:00 am. Make it pause for twenty minutes.
- The ZX Spectrum has accurate integers using binary logic. After any decimal point, every digit is converted into an inaccurate recurring binary which is then added to the running total. This is fuzzy logic and all the duds average each other out so that half the time the number is correct. #fuzzy
- Wow! The source code for the ZX Spectrum has been posted to the Internet Archive by Timex Computer Corp. see my other posts. Right at the end where the 7 byte “ROOT:” routine is Steven has written “***REPLACE WITH NEWTON-RAPHSON SQUARE ROOT***” I used it in the SG03.rom for the ZX81 and now BL81.
- Did you know that the Complete ZX Spectrum source code has been uploaded to Internet Archive by Timex. It was written by Nine Tiles on Zilog Development Studio and Timex obtained the same software. A bit dry but there is a FART joke in there. See the last file. archive.org/details/time...
- The first computer Steve Vickers saw was Turing's Pilot Ace and when the Daily Mirror's reporter "Ruggles" asked Jim Wilkinson at NPL what happens when an error occurs he was told it blows a Raspberry. :-)
- Reposted by Geoff WearmouthWebsite Task Flowchart xkcd.com/3175/
- Reposted by Geoff WearmouthPopular Computing Weekly cover (12/12/1985) READ: archive.org/stream/NH2021_Popul… #zxspectrum #retrogaming
- Reposted by Geoff WearmouthSpeccy clone storms back for Christmas without a shred of Sinclair code
- “The Spectrum” an iconic modern version of the 1982 classic ZX Spectrum, is now on sale in the UK for £59.99 at Amazon. A bargain and the default square root is my fast and accurate 2003 routine. Twenty games included but in my experience it runs everything.
- Reposted by Geoff WearmouthEver wanted to know how your ZX81 ranked against a CRAY supercomputer from 1984? Assuming your eyesight is good enough, now you know.
- Reposted by Geoff WearmouthHere's a Sinclair Microdrive cartridge with a UK pound coin for comparison. We trusted these mini-magnetic tape loops with our valuable data in the 1980s. Totally insane! To be fair, they were actually quite reliable. The tape loop is 5 metres long and stores a minimum of 85 to 100KBytes of data.
- Reposted by Geoff Wearmouth
- Reposted by Geoff WearmouthOne of the most difficult BBC Micro books to obtain. Is there anyone out there that has a copy? I managed to get an ex-library copy that was re-bound. Curious to know how many are actually around. It was withdrawn from sale for legal reasons - it contained an annotated disassembly of BBC BASIC.
- This is the most exciting ZX81 BASIC program ever. It runs on any Sinclair ZX81 model - TS1000 etc. It compares the upcoming LG81 ROM with the host ZX81 ROM. This BASIC program should be downloadable soon but if you want to see how bad your ZX81 is get typing. Developed on iOS ZX81 by Kevin Palser.
- This is the most revealing ZX Spectrum BASIC program ever. It runs on any Sinclair model - Spectrum, TS2068, or any clone. It compares the error-free Looking Glass ROM v1.08 against the host ZX ROM. It should be downloadable by the weekend but if you want to see how bad it your Speccy is get typing.
- Remember in the 1980s when Sinclair and Amstrad dropped the price of The ZX Spectrum. Well RGL have continued the tradition and you can buy The Spectrum for £84.99 - 5% off. Just download the Looking Glass ROM V1.08 from Spectrum Computing or speccy4ever www.smythstoys.com/uk/en-gb/gam...
- Download The Looking Glass ZX Spectrum ROM V1.08 from spectrumcomputing.co.uk/entry/44586/... speccy4ever.speccy.org/_CMS.htm ZX Spectrum ROMs and games.
