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If Sinclair computers had not been sold...I was just having a random thought. If Sinclair Computers (or the rights to them, not sure how it 'worked' back then) had not been sold to Amstrad…
... machine with 80k bytes of RAM (imagine the marketing, more ... dump the 4116 (or equivalent) lower RAM chips. Which is where the ... />
If you retain the lower RAM, and use 64k bit DRAM ... for the upper RAM, you get: 16k (lower RAM) + 64k (upper RAM, some of ... -
Speccy 4A board problemHi all. I was hoping for some help with my Speccy (with 4A Board) before I send it off for repair. When I power it on all looks fine (i.e. copyright …
... it does not have enough RAM to run :-(
... could be a RAM fault, most likely the ‘lower’ RAM (4116 or equivalent ... corrupted due to faulty ‘upper’ RAM.
The quickest and ... try to eliminate the ‘upper’ RAM, you could disable it. Then ... -
upper ram tacks / TR4 socket...[url="https://photos.app.goo.gl/MkqzRCuNCV3EPr9E7"]https://photos.app.goo.gl/MkqzRCuNCV3EPr9E7[/url] you can only replace that pesky TR4 so many t…
... does not care about the lower RAM, it will just grab whatever ... program does need some working RAM...
If there ... want to use a upper RAM replacement module. But before ... broken connections), all the wanted RAM address lines are connected and ... -
doubt about swapping ULA in an issue 2 boardIs it possible to swap a 6C001E-6 ULA type with a 5C112E ? I have this issue 2 board that is not booting, it shows me a black border with horizont…
... DiagROM gives me lower RAM errors, it says all lower RAM is faulty, or ... at the 7805.
RAM IC's are MM5290N
I replaced just one RAM with a modded 4164 ( i ... still shows me an entire lower RAM failure.
I'm ... -
Direct drive LCD screen - looking for information on previous projects people may have attempted.Hi All, My first post, so please forgive and guide if I've posted in the incorrect section. I'm a speccy user from way back in the 80's, but m…
... the Z80 writes to the ‘lower’ RAM area to generate it’s ... -
Were the full Sinclair Loki specs ever actually known?I was just curious. A lot was leaked to the media, but the exact specs seem different depending on source. Some say it could support up to 512x256 an…
... refresh of the 16K byte ‘lower’ RAM did not work as intended ... obviously worked, even if this RAM was only being refreshed by ... and the Z80 accessing the RAM, they did not try to ... -
Anybody got a parts list for an Issue 3b please?I've got a schematic, but does anyone have a parts list with the values just for the resistors and capacitors? Just would save me sometime going thro…
... you use a lower ram board or mod 4164 ram you could do ... -
16pf Capcitors for C72/C73 issue 3b. Can I use 18pf?Looking at the service manual it states to use a 16pf ceramic disc capacitor in positions C72 and C73 on issue 3b boards. Is this very critical in bo…
... power circuit .. and either a lower ram module replacement or some 4164 ... ram with small mod so the ... -
what soldering / disordering equipment do you usemy experience with zx spectrum / amstrad cpc boards 1.cheap solder braid (not good) need to try some better, any recommendations when i looked i go…
... small door ..its removing them lower ram chips that i have to ... -
Are 128K games more likely to crash than 48K ones?Hey, guys. I've been doing some experimenting with various games and even some music demos and apps, and I'm beginning to reach a conclusion that …
... switches ROM and/or RAM banks into/out of ... . But the 16K of ‘lower’ RAM still comes from one set ... 32K of ‘upper’/‘expansion’ RAM still comes from the other ... set of 64K byte RAM chips.
... to load in a diagnostic/RAM test program.
Max RAM for ZX Spectrum gamesHow much RAM can be used for single level/whole game? On tape writing.
... between contended and uncontended RAM is a hardware thing.
RAM there is. This RAM is often known as the ‘lower’ RAM.
RAM. This ‘upper’ RAM is uncontended. The Z80A ... /> In the 128K models, the ‘lower’ 16K which has the screen ...LDIR timings in contended RAM?The 48K Spectrum technical reference page ([URL="http://www.worldofspectrum.org/faq/reference/48kreference.htm"]here[/URL]) describes the detailed ti…
... ]) describes the detailed timings of contended RAM. It gives timings for Z80 instructions ... in, or reading/writing, contended RAM.
I can decipher ... 48K, or double buffered -- paging RAM bank 7 into a 128K ... ]" mean in that table of timings?ZX-81 Ram Pack problemHi! I know this is a ZX Spectrum forum, but I am hoping someone here might be able to help me out... I have posted this to c.s.s. but noone was able…
... original
Sinclair ZX 16k ram pack issue 3 .
lower with POKE 16389,n ... lt; 77 (76 and lower) and then do NEW then ... free (RAMTOP lower than ROM + 3.5k of RAM) then ... a posibility of faulty RAM somewhere on the lower
addresses ? ...SRAM replacement for lower 16KSome time ago I wondered if it were possible to replace the lower 16K RAM of a 16K/48K Spectrum with a single SRAM chip. You know, those pesky 4116 D…
... were possible to replace the lower 16K RAM of a 16K/48K ...How the spectrum generates the video from ramHi everyon, I know that most people here allready know this but i think i found out how the spectrum acctually dispalys stuff and why the LD x, (HL)…
... the first K of ram to video memory and ... cant also read the lower addresses at the same ...
The spectrum has its lower 16K separated from the higher ... is accessing the higher order ram (> 16K) the ULA ... data. Thing is the lower chip only needs to be ...Lower Memory - Why Multiple Voltages?Having spent much of the weekend working on getting my old Spectrum working, my Dad (who is visiting) and I were chatting about the schematic. Given…
... />
Given that the upper RAM in a Spectrum is of ... the 4116 in the lower portion of RAM?
Surely it ...Upper RAM replacement module issues with the DivideI got my new upper ram replacement module from Zorn yesterday and seem to be having some issues. When the machine is without the Divide it boots up …
I got my new upper ram replacement module from Zorn ... manages to boot, the ram passes the memory test i ... When I put the upper ram chips back in place, ... br />
The upper ram are not on the "OKI ... to the upper RAM and uses unusual timings that the replacement ...Timex contended memory timings, the TS2068 kludge board and EXROM at $4000 - $7FFFI haven't seen this documented anywhere yet so I thought I'd share my findings. I've been investigating contended memory timings on the Timex Sinclai…
... 've been investigating contended memory timings on the Timex Sinclair 2068 ... at these locations when the RAM is paged out. I've ... - $7FFF but only when (HOME) RAM is enabled at those locations ... at those addresses whether the RAM is switched in or not ...Paging for 64Kb of Video Ram??? What is the best way to page this?Hi all, I'm just putting together a concept card for a "Loki" style of video card, which supports shadow ( so it fits a normal Speccy ) and also t…
... single 48K video page with RAM relocated to the ROM space ... or 512x192 ) to occupy the lower 48K of memory and leave ...SpeedloadersSince I read Lee Tonks' post about the speedloaded version of MM3 he did, I've been playing around with various speedload routines I found on TTFn & …
... it not run in the lower 16K?
[/QUOTE]
timings off pretty badly.[/QUOTE]
lower 16K RAM and leaned it the hard ... ULA spends holding onto the lower 16K RAM when drawing the screen?SpeedloadersSince I read Lee Tonks' post about the speedloaded version of MM3 he did, I've been playing around with various speedload routines I found on TTFn & …
... BASIC loader) located in lower 16K RAM and leaned it the hard ... , rather than working out the timings in full. It probably wasn ...ULA RAS, CAS cycles, refresh and "snow effect"Hello everyone. I have a question, does anyone observed timings of RAS and CAS generated from ULA? I think there may be answer to where the "snow ef…
... for 16k part of RAM only makes me sure ... will be refreshing the RAM more frequently than 7, ... not required when using NEC4116 ram.
I ... bus being presented to the lower 16K.
... with diagrams, examples and timings later for those who want ...DivIDE+ and 128K HeatsinkI got my DivIDE+ yesterday and i tried it on a 48K+ at first, it worked marvelously on it, no problems at all. Today i desided to try it on my 128 H…
... .
Maybe a higher or lower impedance of this particular Z80 ... which due to timings in the heatsink's RAM (on some of ...Recent talk of developing new SpectrumsHi all, I can see from a few threads on here that some Wossers like Vasil and Aien 8 are interested in developing more powerful Spectrums or improvi…
... a TV without messing up timings or adding a huge amount ... these days).
[*] Replace lower 16K RAM with an SRAM (because those ... ).
[*] Replace upper 32K RAM with another SRAM (because 1 ... to find seller, possibly at lower overall cost & then enjoy ...Memory upgrade for ZX Spectrum 16/48This is external memory upgrade for ZX Spectrum models with 16kB ram. Can be connect also to 48kB models, but need remove 8 dram chips (from sockets …
... includes:
[LIST]
[*]Machine timings (is there any program to ... different machines/peripherals (low, or lower? ;))
[/LIST]
If there ... M has 64 KiB of RAM, but apparently only 48 KiB ... of the Didaktik Gama's RAM must be usable, though.
So what is the best Spectrum?I've had a search and even though i can remember a similar thread somewhere I'll twist it a bit. Whats the best "unmodified" Spectrum? (modification…
... That's down to video timings. The original Speccy has a ... highest clock speed, the most ram, allowed an external tapedeck ... mile. Its got full lower byte I/O decoding so ... expand it to 176K of RAM (pageable in 8K chunks ... hooking up a single 128K RAM chip to the MMU. ...
