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Spectrum 16K Issue 3Hi! I just received a Spectrum 16K, which turns out to be an Issue 3. Is it really that rare? If not, I?d like to upgrade it to 48K. There are 12 em…
... a random value in the upper 32K (say 60000) and PEEK ... (from 0 to 255) to upper RAM in consecutive addresses, then read ... ? :) ) - modify values in upper RAM and see if other RAM addresses change when ... -
Spectrum 16K Issue 3Hi! I just received a Spectrum 16K, which turns out to be an Issue 3. Is it really that rare? If not, I?d like to upgrade it to 48K. There are 12 em…
... a random value in the upper 32K (say 60000) and PEEK ... (from 0 to 255) to upper RAM in consecutive addresses, then read ... ? :) ) - modify values in upper RAM and see if other RAM addresses change when ... -
My 48K Speccy has died.Hi fellow WoSer's! Wondering if you could help me with my rubber key 48k Spectrum, which died on me this afternoon. It is one I prevoiusly fixed up j…
... behaviour caused by bad ram. Find a RAM tester written in z80 ... was able to diagnose the upper ram of mine in this way ... turn out to be bad ram, speak to Ian from Mutant ... -
Some stupid 16K questions...Starting with... 1. Should a 16K Spectrum that's been upgraded to 48K behave [I]exactly[/I] like a 48K Spectrum? i.e. should the machine test/clear…
Most likely a faulty 48K. You should test address 32768 with all binary bit patterns. Poking and Peeking numbers 85 and 170 might be sufficient.
A dead (upper) RAM chip often is significant warmer as his colleagues. -
Some stupid 16K questions...Starting with... 1. Should a 16K Spectrum that's been upgraded to 48K behave [I]exactly[/I] like a 48K Spectrum? i.e. should the machine test/clear…
... Spectrum 48k boards with faulty upper RAM have been sold as 16k ... -
Some stupid 16K questions...Starting with... 1. Should a 16K Spectrum that's been upgraded to 48K behave [I]exactly[/I] like a 48K Spectrum? i.e. should the machine test/clear…
It sounds like a fault in the upper RAM.
Try this program: [url]http://www.worldofspectrum.org/forums/showthread.php?p=656549#post656549[/url]
It'll probably let you work out which RAM ICs are faulty. -
16k --> 48kI bought a zx and found out it was a 16k since when I execute PRINT PEEK 23733 I get 127 Does it mean I get a lesser model? What limitations do I h…
... of a fault in the upper RAM (which is fairly common).
upper RAM, if present is made up ... -
16k --> 48kI bought a zx and found out it was a 16k since when I execute PRINT PEEK 23733 I get 127 Does it mean I get a lesser model? What limitations do I h…
... of a fault in the upper RAM (which is fairly common).[/QUOTE ... -
16k --> 48kI bought a zx and found out it was a 16k since when I execute PRINT PEEK 23733 I get 127 Does it mean I get a lesser model? What limitations do I h…
... . Tell it to test the upper RAM.
The easiest way ... -
16k --> 48kI bought a zx and found out it was a 16k since when I execute PRINT PEEK 23733 I get 127 Does it mean I get a lesser model? What limitations do I h…
... . Tell it to test the upper RAM.
The easiest way ... -
16k --> 48kI bought a zx and found out it was a 16k since when I execute PRINT PEEK 23733 I get 127 Does it mean I get a lesser model? What limitations do I h…
It looks like a 48K Spectrum with an upper RAM fault. Give me a moment and I'll tell you more... -
16k --> 48kI bought a zx and found out it was a 16k since when I execute PRINT PEEK 23733 I get 127 Does it mean I get a lesser model? What limitations do I h…
... suggests that bit 4 in upper RAM is stuck high.
If the present upper RAM ICs are soldered in place ... -
16k --> 48kI bought a zx and found out it was a 16k since when I execute PRINT PEEK 23733 I get 127 Does it mean I get a lesser model? What limitations do I h…
... suggests that bit 4 in upper RAM is stuck high.
If the present upper RAM ICs are soldered in place ... -
16k --> 48kI bought a zx and found out it was a 16k since when I execute PRINT PEEK 23733 I get 127 Does it mean I get a lesser model? What limitations do I h…
TKMEM - the 128K interface for 16K SpectrumsHello all! Here in Brazil, we have made a small production of an interface, totally based on Velesoft?s memory expansion ([url]http://velesoft.speccy…
[QUOTE=Crisis;672363]so now there is beside the 48k upgrade kit a 128k upgrade interface, wow ![/QUOTE]
It's not perfect, but works very well.
And you must disable the 32k upper ram. :DTKMEM - the 128K interface for 16K SpectrumsHello all! Here in Brazil, we have made a small production of an interface, totally based on Velesoft?s memory expansion ([url]http://velesoft.speccy…
... /> [/QUOTE]
The upper 32KB of RAM must be disabled. This ... task for TK90X. If the RAM chips were plugged into sockets ... />
I guess that the upper RAM could be easily disabled in ...TKMEM - the 128K interface for 16K SpectrumsHello all! Here in Brazil, we have made a small production of an interface, totally based on Velesoft?s memory expansion ([url]http://velesoft.speccy…
... /> Some ZX Spectrum boards have upper ram chips in sockets then is ... without sockets must be disable upper ram 32kB (for example via cut ...TKMEM - the 128K interface for 16K SpectrumsHello all! Here in Brazil, we have made a small production of an interface, totally based on Velesoft?s memory expansion ([url]http://velesoft.speccy…
[QUOTE=TK90XFan;674886]The upper 32KB of RAM must be disabled. This is ... task for TK90X. If the RAM chips were plugged into sockets ... ;674886]I guess that the upper RAM could be easily disabled in ... lock the internal 32K of RAM, supply +5V on pin 4B ...TKMEM - the 128K interface for 16K SpectrumsHello all! Here in Brazil, we have made a small production of an interface, totally based on Velesoft?s memory expansion ([url]http://velesoft.speccy…
... can disable the 32k of upper RAM by a wire or jumper ...TKMEM - the 128K interface for 16K SpectrumsHello all! Here in Brazil, we have made a small production of an interface, totally based on Velesoft?s memory expansion ([url]http://velesoft.speccy…
... can disable the 32k of upper RAM by a wire or jumper ...Beta diskJust something that's been bugging me for a while, is the 128k beta disk interface wired differently to the beta 48k as a piece of hardware, or as I …
But could an original Beta Disk interface be used with a 128k machine, for instance allowing a 128k game to be loaded by permitting paging of the upper Ram to occur?The new Superfo cloneHi In the spanish forum speccy.org some guys and me have optimized the superfo clon to have less ICs. The actual design has 39 ICs versus the 45 ICs…
... the Z80 to access the upper ram without collision. But when the ... doesn't need the video ram, the Z80 has unhindered access ... is coupled to the video ram through resistors, in this undecoded ...maximum addressable RAM for a Z80 using bank switching?What is the maximum addressable RAM for a Z80 using bank switching? The Enterprise64 home computer could address up to 4MB, is this the limit for a …
... 256 banks of 32K SRAM (upper RAM).
Never made more than ... as a removable storage interface, RAM with battery or ROM cartridges ...maximum addressable RAM for a Z80 using bank switching?What is the maximum addressable RAM for a Z80 using bank switching? The Enterprise64 home computer could address up to 4MB, is this the limit for a …
... configure your bank switched RAM as a RAM disc, you also need ... or 48-64K in the upper RAM), the software I wrote 'saw ... ' the RAM disc as a series of ... , and dynamically mapped to the RAM disc, with used/unused sectors ...Spectrum 128K +2 problemhello, i am try to repair my spectrum 128k +2 grey, i remove all ram chips and i have some new ones spares, now i have remove all ram chips, i want …
... - IC32 "main" RAM including screen RAM
IC17 - IC24 "upper" RAM.
Not ... the +2, but if the upper RAM is not present on a ...Spectrum 128K +2 problemhello, i am try to repair my spectrum 128k +2 grey, i remove all ram chips and i have some new ones spares, now i have remove all ram chips, i want …
... - IC32 "main" RAM including screen RAM
IC17 - IC24 "upper" RAM.
Not ... the +2, but if the upper RAM is not present on a ...ZX8401 / PCF1306P / Amstrad 40058 for 48K and 128KZX8401 = PCF1306P = Amstrad 40058, let's get started with that. These chips are used as surrogates. Most of us might think those chips were only use…
... /> So that chip is for upper memory adressing, check out the ... copes with paging, leaving the upper memory logic intact, like the ... half' of the 4164/4532 upper ram chips, so Sinclair could buy ... paging ;)
"Now that all upper ram chips we order fully work ...Flashing coloured blocks - diagnosisHiya, hope this is the right place for this... Was given an Issue 2 48K by a someone yesterday that hasn't been powered on in 20 years, which works …
... suggests a fault in the upper RAM, not the lower. This is ... 're able to, try the RAM test program I created and ... . Try it against the upper and lower RAM and leave it running ...Flashing coloured blocks - diagnosisHiya, hope this is the right place for this... Was given an Issue 2 48K by a someone yesterday that hasn't been powered on in 20 years, which works …
Brap brap! It's faulty upper RAM:
[IMG]http://ubuntuone.com/48eEV5ixlM8GGIlyd00iVr[/IMG]
Thanks so much, great little utility! How do I go about identifying which IC# is the offending chip?Flashing coloured blocks - diagnosisHiya, hope this is the right place for this... Was given an Issue 2 48K by a someone yesterday that hasn't been powered on in 20 years, which works …
... ' the contacts.[/QUOTE]
The upper RAM is soldered to the board ... it successfully checks the lower RAM?
Will definitely be ... to swapping out the faulty RAM.
