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Someone can help me to fix my Zx Spectrum?I did a video about the startup: [url]http://dl.dropbox.com/u/1566495/ZXSPECTRUM03.mp4[/url] I have replaced the ULA with a working one (same proble…
... , and thus disable the upper 32K. Not airtight, but ... the upper 32K: if faulty, it usually means bad RAM ... ]
Uhm... no. The upper 32K is just an optional ... Spectrum needs the [B]lower 16K RAM[/B] to be usable. ... regardless of what the upper 32K RAM is doing. -
damaged spectrum+ (blinking squares)Hi, Sorry for my poor english, but I couldn't find on family forums any remedy for my hardware problem with my first speccy in my life :) I've bought…
... circuitry that serves video + lower 16K RAM chips (4116 or equivalent type ... ) TR4. Often followed by a failure of 1 or more of ... , temporary replacement for that lower 16K in any easy manner, while ... makes diagnosis of if/which RAM chips are gone, difficult.
Memory mapping: Pentagon compatibility?I'm writing something that will rely heavily on the Spectrum's ability to switch screen buffers in hardware (port 0x7FFD). The original Spectrum 128K…
... is to use the video RAM paging hardware.
RAM 5 and RAM 7, writing both ... fit my entire program into 16K, in RAM bank 2.
< ... RAM 7 can be written from RAM 2, and video-RAM 5 from RAM ... the upper border, I can place it in RAM 5.< ...48K Speccy Repair Log.Some people may know my love for writing up my repairs of arcade PCBs on various forums so thought I would do the same for this little fella. Had th…
... 64Kbit chips to implement the upper memory bank (the last 32KBytes ... this, because a 16K machine has sockets on upper memory chips, two ... suffered some damage in the upper memory. As the damaged didn ... mirrored from the third 16K page, so the RAM test that the ...Flash based rom replacement board for +2A/+3I'm sure I already started a thread about this, but I can't find it... Anyway, this post's to say that I've just sent off the order for the printed …
... living on for example the upper bank I would think. So ... you boot with the upper bank selected, load in your ... in that rom, giving you 16k of space for your code ... normally load from tape into ram when the machine powers up ...Speccy repairs?I've finally got round to testing all the various Spectrums that I seem to have accumulated over the years and discovered that "my" two machines (i.e…
... difficult to say whether upper or lower RAM is bad, most of ... br />
Most likely bad RAM also.
[quote]
Again, most likely bad RAM.
[quote]
[*] ... data sheet explains why. The failure of this power supply is ...Whole upper memory lostHi! I own a rubber key Spectrum with 48K RAM. Suddenly it lost it's whole upper memory. All diagnostic programs says that it's 16K model with workin…
... works for you because the failure in your memory is caused ... RAS/CAS circuit inside the RAM, or the tri-state condition ... all the memory in the upper region. The ROM memory test ...Whole upper memory lostHi! I own a rubber key Spectrum with 48K RAM. Suddenly it lost it's whole upper memory. All diagnostic programs says that it's 16K model with workin…
... , is a possible failure mode for RAM chip and/or circuit ... single bit failure is enough to declare a RAM chip failure. Since in ... :smile:
True the upper 32K logic IC's could ... as repair method. Luckily the upper 32K normally sits in sockets.48k Out of memoryIv just had a 48k Speccy arrive today. The keyboard wasnt working right so I changed that. Now when I tried to load Cyclone it started to load ok fo…
... upper 32K of RAM is more straight forward than the lower 16K ... .
You can buy off the shelf replacement RAM ... out what type of RAM your Spectrum currently has ... RAM banks that make up the upper 32K of RAM. Each RAM ... of the eight RAM chips require replacing ...Dumb question but deep answer wantedWhy is the ram on the 48k made up of 8 chips. Both upper 32k and lower 16k (4116) are set up like this. Taking the 4116 as an example this us a singl…
... the ram on the 48k made up of 8 chips. Both upper ... 32k and lower 16k (4116) are set ... example this us a single 16k dram chip, so why the ... kilobytes.
it's 16k * 1 bit, so there are ... a bit of each byte 16k in totalUpgrading 16k MemoryHi All I have a fully working issue 2 16k spectrum and a broken issue3 48k spectrum (It's showing the black and white bars and some flashing blocks)…
... now works! (albeit as a 16k). I tried loading jetpac on ... be a fault in the upper 32kb ram or logic chips. I ...Upgrading 16k MemoryHi All I have a fully working issue 2 16k spectrum and a broken issue3 48k spectrum (It's showing the black and white bars and some flashing blocks)…
... a fault in the upper 32kb ram or logic chips. I ... that failed RAM chip(s) in the [I]upper[/I] 32K ... upper 32K simply wouldn't be used, you'd have a 16K ... you have maximum number of upper 32K chips inserted & ... x 8 bit static RAM chip for upper 32K (soldered on ...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…
... these days).
[*] Replace lower 16K RAM with an SRAM (because those ... antique 4116 RAM chips die like fleas, and ... a PITA).
[*] Replace upper 32K RAM with another SRAM (because 1 ... RAM chip is simpler than 8, ...Upgrading the Humble Spectrum 128 +2 (Grey)Hello there my fellow WoS'ers I am at a subtle in-pass in my wants for one of my +2 motherboards. I received this mobo, DOA in a job lot from fleab…
... with say, SEBasic in lower 16K of the Boot ROM I ... an put that in the upper 16K?
would there be ... 4k of rom. without extra ram you'd have to use ... one of the speccy's ram pages for buffers etc, like ...binutils questionSince there's a few people using binutils these days I thought I'd give it a go and see whether it solves my hunt for a replacement assembler/librari…
... out the lower 16K RAM, the screen area, and the upper 32. I ... use and also honouring the 16K/32K split if needed.
Spectrum not working, can anyone help this lady?[URL="http://www.retrogamer.net/forum/viewtopic.php?f=6&t=29734#p674152"]http://www.retrogamer.net/forum/viewtopic.php?f=6&t=29734#p674152[/URL]
... it's the most common failure). A failure in one of the ... it's probably a damaged RAM in the lower bank. If ... rails, and if the 16K lower RAM bank is not being fed ...Dead Spectrum+Hi! Any suggestions where to start finding what's broken: Spectrum+ with issue 6A motherboard and nothing on TV. Top row of the upper memory chips g…
... short circuit on low bank RAM. TR5 (ZTX213) rarely becomes damaged ... any chip in the low RAM bank, with a little of ... booting as normal (although with 16K RAM if upper memory was defective). If ... in the contended bank (low 16K RAM) are damaged, and beyond this ...writing an emulator-newbie needs helpHi, this is my first post here. I decided to write a minimalistic emulator of ZX Spectrum-no emulation of advanced peripherals, no emulation of sound…
... Speccy with lower 16K as ROM and upper 48K as RAM works or ...writing an emulator-newbie needs helpHi, this is my first post here. I decided to write a minimalistic emulator of ZX Spectrum-no emulation of advanced peripherals, no emulation of sound…
... Speccy with lower 16K as ROM and upper 48K as RAM works or ...writing an emulator-newbie needs helpHi, this is my first post here. I decided to write a minimalistic emulator of ZX Spectrum-no emulation of advanced peripherals, no emulation of sound…
... Speccy with lower 16K as ROM and upper 48K as RAM works or ... the address is ROM or RAM. This penalizes all the writes ... easy implementation of +3 "all RAM" modes and the emulation of ... as the Multiface (changes the 16k Spectrum ROM by 8k ROM ...Requesting a little help to identify the purpose of this 'add-on' to my Issue 2Hi everyone First of all it's my first post here so please go easy on me! I'm grateful to be accepted into your fine little club :smile: I probabl…
... with the upper 32K RAM. The 'dead cockroach' fix & upper 32K RAM are ... are OK
[*]Load some 16K only programs and/or try ... there. A machine with lower 16K RAM okay is better than an ... how to locate, and fix upper 32K RAM problems.
[*]Be careful ...Repairing a faulty 48K issue 2.I am investigating one of a pair of non-working issue 2 48K Spectrums that have been sitting in a cupboard untouched for quite a few years. I haven…
... over the display area of RAM and lowering the RAMTOP and ... top half of the lower 16K of RAM.
It quickly ... an area of the upper 32K of RAM for a while too ... /control signal for the lower RAM.
Are any of ...Colour blocks on displayHi all, I have just acquired another Sinclair product, my first one being a C5, it's a 48K ZX Spectrum. It shows colour blocks on the display when p…
The lower 16K of RAM is formed by IC6-IC13 ... to the lower RAM that led to the failure. If you don ...3D Deathchase on the Commodore 643D Deathchase has been ported to the C64, at least according to Micro-Mart. According to this week's MM, the port is called Hell Racer, and here's a …
... not using an external colour RAM like the C64 does (saving ... did the C16 have literally 16k of memory? If so, ... />
It's a 16K machine yes, with 2,000 ... assigned to screen and colour RAM at start up (these ... to 2MHz mode in the upper and lower borders to get ...AY-interface for ZX81 (at last ;) )Hi, it exists finally ;) - compatible with the most standard one - ZonX. [url]http://www.sellmyretro.com/offer/details/Brand_New_Sinclair_ZX81_MrX_A…
... does it only expand the RAM to 32K and not 64K ... like some older ZX81 RAM expansion packs?[/QUOTE]
RAM a zeddy can carry. The upper 16K is effectively ...Outrun Europa in colourSwainy suggested that he'd like to try his luck with Outrun Europa colorful graphics and see if they can be improved. Let's give him the chance :) A…
... hardware isn't a complete failure. The prototype has been fixed ... everything written for any Spectrum 16K/48K/128K, Timex TC2048, Tx2068 ... with the same amount of RAM available as on a BBC ... else that needs an all-RAM mode (such as the IF2 ...128k gone badHi All, Turned my 128k on this morning and... [img]http://www.w.angold.btinternet.co.uk/bad128small.jpg[/img] Can anyone help? whats the most lik…
Almost certainly bad RAM (one or more bad RAM ICs)
If you have a DivIDE or any other piece of hardware that makes a 128K come up in USR 0 mode, if the failure is in upper memory it's very easy to find using BASIC POKE and PEEK.Issue 2 Failed 48k to 128k upgradeI have been trying to upgrade my Issue 2 with the help of Velesoft, using this schematic; [IMG]http://i764.photobucket.com/albums/xx284/arioch1973/4…
... my upgraded Issue 2 16k machine (replace lower ram with 4164s asap ... since I have noticed they survive failure ...
