Geoff Wearmouth
@warmtoffee.bsky.social
Press plastic for a living but love the touch of rubber. Assembler of Gosh Wonderful and Looking Glass ZX Spectrum ROMs.
Amazon sold out. smythstoys still has ‘em for £59.99. Second best is PLAION at £67.49 until tonight.
Get your ZX Spectrum clone here.
Get your ZX Spectrum clone here.
December 1, 2025 at 2:52 PM
Amazon sold out. smythstoys still has ‘em for £59.99. Second best is PLAION at £67.49 until tonight.
Get your ZX Spectrum clone here.
Get your ZX Spectrum clone here.
I have just checked arounsband PLAION have it for 67.50 while Smyths Toys and Amazon Prime have it for £59.99 although check out the Amazon delivery. It says February. Probably a mistake.
November 28, 2025 at 1:17 PM
I have just checked arounsband PLAION have it for 67.50 while Smyths Toys and Amazon Prime have it for £59.99 although check out the Amazon delivery. It says February. Probably a mistake.
“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.
November 23, 2025 at 5:59 PM
“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.
And there is more from Andrew on Page 167
November 23, 2025 at 12:21 AM
And there is more from Andrew on Page 167
This is the one I bought first but it was £15. If you leave a good review it goes up. There are plenty of others but this does have an extra 13 rolls of paper.
ebay.us/m/AfMpvl
ebay.us/m/AfMpvl
November 21, 2025 at 3:03 PM
This is the one I bought first but it was £15. If you leave a good review it goes up. There are plenty of others but this does have an extra 13 rolls of paper.
ebay.us/m/AfMpvl
ebay.us/m/AfMpvl
These bluetooth printers cost between £8 and £15 and could be adapted to USB data. They need the occasional recharge. My Alphacom 32 buffered the ZX81 and ZX Spectrum output until it had received two lines and then output them shimmying right and left.
Adapting would not cost much.
Jolly useful.
Adapting would not cost much.
Jolly useful.
November 21, 2025 at 1:44 PM
These bluetooth printers cost between £8 and £15 and could be adapted to USB data. They need the occasional recharge. My Alphacom 32 buffered the ZX81 and ZX Spectrum output until it had received two lines and then output them shimmying right and left.
Adapting would not cost much.
Jolly useful.
Adapting would not cost much.
Jolly useful.
On the ZX Spectrum Looking Glass ROM I had more room and after removing the red Z80 lines I added an iteration counter in K-DATA 23565. Many roots only require 1 try while most take 5 loops for a perfect solution.
The accompanying BASIC program shows the binary roots and loop counter.
The accompanying BASIC program shows the binary roots and loop counter.
November 7, 2025 at 6:14 PM
On the ZX Spectrum Looking Glass ROM I had more room and after removing the red Z80 lines I added an iteration counter in K-DATA 23565. Many roots only require 1 try while most take 5 loops for a perfect solution.
The accompanying BASIC program shows the binary roots and loop counter.
The accompanying BASIC program shows the binary roots and loop counter.
I wrote that routine over 20 years ago on the sg81.rom which is preserved on wayback. The routines that use sqr - asn,acs use mem-0 to mem-2 for several Chebyshev series generations as does the original sqr function which uses to_power,ln and exp. The original ZX81 sqr uses mem-3 indirectly (exp).
November 7, 2025 at 1:10 PM
I wrote that routine over 20 years ago on the sg81.rom which is preserved on wayback. The routines that use sqr - asn,acs use mem-0 to mem-2 for several Chebyshev series generations as does the original sqr function which uses to_power,ln and exp. The original ZX81 sqr uses mem-3 indirectly (exp).
The video is quite dramatic for such a short ZX Spectrum program. Wait for it. Watch the lower left hand corner.
November 4, 2025 at 12:26 AM
The video is quite dramatic for such a short ZX Spectrum program. Wait for it. Watch the lower left hand corner.
40 years ago I had this ZX Spectrum BASIC type-in published in Popular Computing Weekly. The magazine used my Alphacom 32 thermal printout which stands out with a bold font.
November 4, 2025 at 12:21 AM
40 years ago I had this ZX Spectrum BASIC type-in published in Popular Computing Weekly. The magazine used my Alphacom 32 thermal printout which stands out with a bold font.
An interesting Letters page with two interesting letters about the Spectrum. The first on the inviting space at the end of the ZX Spectrum ROM. The other by Andrew Pennell refers to the 09/09/1982 magazine by Dr. Ian Logan which detailed bugs and Andrew lists a load of bugs in the Vickers manual.
October 26, 2025 at 3:36 PM
An interesting Letters page with two interesting letters about the Spectrum. The first on the inviting space at the end of the ZX Spectrum ROM. The other by Andrew Pennell refers to the 09/09/1982 magazine by Dr. Ian Logan which detailed bugs and Andrew lists a load of bugs in the Vickers manual.
In both the ZX81 and ZX Spectrum the division routine misses a shift and the 34th bit is lost.
As Dr. Frank O’Hara explained a jump to DIV-34TH must be made and not to DIV-START. After division the mantissa is not normalised. Normalisation pulls in the 33rd unset bit from A and bit 34 moves to 33.
As Dr. Frank O’Hara explained a jump to DIV-34TH must be made and not to DIV-START. After division the mantissa is not normalised. Normalisation pulls in the 33rd unset bit from A and bit 34 moves to 33.
October 20, 2025 at 9:39 PM
In both the ZX81 and ZX Spectrum the division routine misses a shift and the 34th bit is lost.
As Dr. Frank O’Hara explained a jump to DIV-34TH must be made and not to DIV-START. After division the mantissa is not normalised. Normalisation pulls in the 33rd unset bit from A and bit 34 moves to 33.
As Dr. Frank O’Hara explained a jump to DIV-34TH must be made and not to DIV-START. After division the mantissa is not normalised. Normalisation pulls in the 33rd unset bit from A and bit 34 moves to 33.
Here is the Z80 source code from my ZX Spectrum ZEUS assembler.
October 16, 2025 at 10:15 AM
Here is the Z80 source code from my ZX Spectrum ZEUS assembler.
And on Page 44, yours truly with a short ZX Spectrum type-in “Spherical Objects”. No image or Z80 source code but that is fixed now.
October 16, 2025 at 10:06 AM
And on Page 44, yours truly with a short ZX Spectrum type-in “Spherical Objects”. No image or Z80 source code but that is fixed now.
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 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.
October 8, 2025 at 7:18 PM
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 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.
A nice Page 179 on BIN, ATTR and pure colours.
Amstrad messed up that text in all their manuals but 30 years later in 2014 Steve’s penguin had the last word on BIN 010 (It’s 2 not 4).
Amstrad messed up that text in all their manuals but 30 years later in 2014 Steve’s penguin had the last word on BIN 010 (It’s 2 not 4).
October 8, 2025 at 6:53 PM
A nice Page 179 on BIN, ATTR and pure colours.
Amstrad messed up that text in all their manuals but 30 years later in 2014 Steve’s penguin had the last word on BIN 010 (It’s 2 not 4).
Amstrad messed up that text in all their manuals but 30 years later in 2014 Steve’s penguin had the last word on BIN 010 (It’s 2 not 4).
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.
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.
October 8, 2025 at 11:49 AM
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.
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.
It’s all happening in 1982. Dr. Ian Logan reveals three ZX Spectrum bugs on the letters page and on Page 19 there is a competition to win a newly launched Jupiter Ace.
October 5, 2025 at 10:59 PM
It’s all happening in 1982. Dr. Ian Logan reveals three ZX Spectrum bugs on the letters page and on Page 19 there is a competition to win a newly launched Jupiter Ace.
If, as I expect, those ZX Spectrum machines have sold out then you can go to Amazon Prime,
smythstoys.com , Argos etc. and have a much more exciting model for £89.99 😊. With my LG18 v1.08 ROM installed it will run all 48K software. You can get it all on one SD Card too.
smythstoys.com , Argos etc. and have a much more exciting model for £89.99 😊. With my LG18 v1.08 ROM installed it will run all 48K software. You can get it all on one SD Card too.
September 28, 2025 at 3:10 PM
If, as I expect, those ZX Spectrum machines have sold out then you can go to Amazon Prime,
smythstoys.com , Argos etc. and have a much more exciting model for £89.99 😊. With my LG18 v1.08 ROM installed it will run all 48K software. You can get it all on one SD Card too.
smythstoys.com , Argos etc. and have a much more exciting model for £89.99 😊. With my LG18 v1.08 ROM installed it will run all 48K software. You can get it all on one SD Card too.
Isometric ZX Spectrum game by Chris Smith who designed my “The Spectrum” machine and has been a leading light on the Spectrum scene for over thirty years. Author of the book about “The ZX Spectrum ULA”.
September 28, 2025 at 2:17 PM
Isometric ZX Spectrum game by Chris Smith who designed my “The Spectrum” machine and has been a leading light on the Spectrum scene for over thirty years. Author of the book about “The ZX Spectrum ULA”.
That is a great issue with Nigel Searle explaining that the QL might have a Z80 co-processor and, after his Beijing visit, ZX Spectrums will be assembled there.
Best bit is this letter from Paul Ockenden whose type-in reveals all the ZX Spectrum Scrabble words.
That is my weekend taken care of.
Best bit is this letter from Paul Ockenden whose type-in reveals all the ZX Spectrum Scrabble words.
That is my weekend taken care of.
September 26, 2025 at 10:05 PM
That is a great issue with Nigel Searle explaining that the QL might have a Z80 co-processor and, after his Beijing visit, ZX Spectrums will be assembled there.
Best bit is this letter from Paul Ockenden whose type-in reveals all the ZX Spectrum Scrabble words.
That is my weekend taken care of.
Best bit is this letter from Paul Ockenden whose type-in reveals all the ZX Spectrum Scrabble words.
That is my weekend taken care of.
My virtual computer written in ZX Spectrum BASIC highlights some more errors in the original 1982 ZX Spectrum. My latest ROM is error free.
September 26, 2025 at 10:42 AM
My virtual computer written in ZX Spectrum BASIC highlights some more errors in the original 1982 ZX Spectrum. My latest ROM is error free.
Inspired by a S. McCarthy ZX Spectrum f.p. program my Virtual Computer has a flexible exponent and mantissa and will convert a decimal number to perfect binary.
The only data from the ZX Spectrum is the bright yellow exponent and mantissa. Wrong digits will be highlighted in red.
The only data from the ZX Spectrum is the bright yellow exponent and mantissa. Wrong digits will be highlighted in red.
September 24, 2025 at 11:16 PM
Inspired by a S. McCarthy ZX Spectrum f.p. program my Virtual Computer has a flexible exponent and mantissa and will convert a decimal number to perfect binary.
The only data from the ZX Spectrum is the bright yellow exponent and mantissa. Wrong digits will be highlighted in red.
The only data from the ZX Spectrum is the bright yellow exponent and mantissa. Wrong digits will be highlighted in red.
Back in 2014 Dr. Steve Vickers made some lecture slides available on his University website. I used his decimal to binary conversion routines to expand on a floating point display program I had typed in. This created a virtual computer with correct exponent and mantissa to test my ZX Spectrum ROMs.
September 24, 2025 at 10:49 PM
Back in 2014 Dr. Steve Vickers made some lecture slides available on his University website. I used his decimal to binary conversion routines to expand on a floating point display program I had typed in. This created a virtual computer with correct exponent and mantissa to test my ZX Spectrum ROMs.
The Looking Glass ROM V1.08 for the 48K ZX Spectrum is now available for download with documentation.
speccy4ever.speccy.org/_CMS.htm
This is the most accurate ROM ever available for the ZX Spectrum and is the equal to Microsoft Binary Format 9-digit BASIC. Say goodbye to dodgy figures.
speccy4ever.speccy.org/_CMS.htm
This is the most accurate ROM ever available for the ZX Spectrum and is the equal to Microsoft Binary Format 9-digit BASIC. Say goodbye to dodgy figures.
September 23, 2025 at 11:45 AM
The Looking Glass ROM V1.08 for the 48K ZX Spectrum is now available for download with documentation.
speccy4ever.speccy.org/_CMS.htm
This is the most accurate ROM ever available for the ZX Spectrum and is the equal to Microsoft Binary Format 9-digit BASIC. Say goodbye to dodgy figures.
speccy4ever.speccy.org/_CMS.htm
This is the most accurate ROM ever available for the ZX Spectrum and is the equal to Microsoft Binary Format 9-digit BASIC. Say goodbye to dodgy figures.