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Announcing: The +2A/+3 FLASH ROM adapter boardAs I've mentioned in a couple of other threads, this project is coming along quite well now, so I thought I'd post some details up here. I've built …
... control the selection of the upper and lower 64k banks of ... connection to the spectrum's ram write line (connected to the ... a flying lead to a ram IC) allowing the FLASH rom ... -
memory chips spectrum +Hi with regards to memory chips the ones in there are tms4116 in the lower memory.there is some on ebay MCM4116BP20 can i mix these with tms ones or …
... /416-3/MN5290-2 4116 150ns
You put ... ://cgi.ebay.co.uk/VINTAGE-RAM-MK4116N-3GP-MOSTEK-16PIN-DIP ... UPD416-3 chips is a 150ns :-O
bye
16 K Sinclair Spectrums Still Available?Hi. I wanted to know if the 16 K Sinclair Spectrums are still available to buy. I have looked around on the net without any success. Maybe someone kn…
... ;415148]Only for testing: Which ram must be removed on an ... near the beeper are the upper 32K. On an issue 2 ...16 K Sinclair Spectrums Still Available?Hi. I wanted to know if the 16 K Sinclair Spectrums are still available to buy. I have looked around on the net without any success. Maybe someone kn…
the lower ram 16k should not be touched ... function, you mean remove the upper 32k by the beeper tbh ...Looking for some 48k RAM (upper 32k bank)Greetings, I was wondering where I could find some upper RAM for a 48k (issue 4A). It's the Texas Instruments TMS4532-20NL4 P8419 (or any compatib…
... ]
[*]Remove any existing upper 32K RAM chips (=pull 4164's from ...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…
... a -5V used by lower RAM).
[*]Check clock signals (video ... signal(s) are present.
[*]Upper 32K present/socketed? Remove (to ... check function.
[*]Replace lower RAM (because that's [I]very ...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…
... s 2 resistors in the upper 32K control logic (R70 ... , and thus disable the upper 32K. Not airtight, but ... the upper 32K: if faulty, it usually means bad RAM ... br /> Uhm... no. The upper 32K is just an optional ... regardless of what the upper 32K RAM is doing.Where is the other side from the ZX 48 PCB?Has anyone the other side from the PCB? [url]ftp://ftp.worldofspectrum.org/pub/sinclair/technical-docs/ZXSpectrumIssue3-PCB_Bottom.gif[/url] Micky
... instead of 4116 for low RAM, and a YPrPb to RGB ... can even use static RAM for the upper 32KB memory, simplifying the ...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…
... 'd be doubting between lower RAM chip(s), Z80, or perhaps ... I'd just unsolder lower RAM IC's + Z80 now, test ... you... (btw. too bad the upper 32K isn't socketed, so ...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 ... advantage to gain by writing RAM 5 at 0x4000. This ... RAM 7 can be written from RAM 2, and video-RAM 5 from RAM ... drawing the upper border, I can place it in RAM 5.< ...Z80 Machine Code Question...Hi Folks, I know not strictly a BASIC question but I have started to learn Z80 machine code - 25 years too late! :smile: I have been reading a book…
... MHz Z80. That's entire upper 32K RAM (8000-FFFFh) filled in ...Spectrum hangs upWhat might be problem when my ZX Spectrum 48K (rubber keys) hangs up after few minutes play? It had memory problems but i changed (or an expert did i…
And about those upper memory chips: only text in chips are M5K4164ANP 54821X -15
For me it tells only that chips model is 4164 and they are 150ns(?)
Ippe48K 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 ... 16K machine has sockets on upper memory chips, two multiplexers, the ... suffered some damage in the upper memory. As the damaged didn ... third 16K page, so the RAM test that the ROM performs ...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 ... 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]
[*]Seems ... />
With suspect bad lower RAM you also need to check ...Help with broken SpectrumHi There, Just received a ZX Spectrum computer. It's an issue 3B (48k version). When I power it up (9V centre pin -V) nothing happens. It's complete…
... that is on the lower RAM chips (lower left corner of ... be:
Pin 16 (upper right corner pin) = GND = same ... right) = +5V
Pin 1 (upper left) = -5V
Pin 8 ... good idea to remove the upper 32K (RAM chips in middle of ...The Sadness of my Decaying Speccies.I've been avidly collecting ZX Spectrums since the late 90's and whilst at the time of the late 90's and early millennium my Spectrums and associated…
For this, static RAM is better: it draws less ... not as vulnerable as dynamic RAM. Besides, as he says, all ... by the data lines from upper memory. Check the datasheet!
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…
... that's just a failed RAM chip, or perhaps a ... bad contact between a RAM chip and the IC ... BASIC?) that goes over all upper 32K memory locations. For each ... , and schematic shows which RAM chip corresponds what that bit ... (s). Re-socket that RAM chip a few times in ...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…
... 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…
... a possible failure mode for RAM chip and/or circuit board ... is enough to declare a RAM chip failure. Since in order ... ... :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…
The upper 32K of RAM is more straight forward ... off the shelf replacement RAM but you have to ... work out what type of RAM your Spectrum currently has. ... 8 RAM banks that make up the upper 32K of RAM. Each RAM ... two of the eight RAM chips require replacing so ...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 ...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…
[QUOTE=Alcoholics Anonymous;499468]Tying RAM speed to CPU clock is ... in 'page reads' (to avoid RAM wait states, remember the ARM2 ... faster than the 150ns speed rating of the 4116 RAM. DRAM effectively ... access data within a specific RAM page).
And ...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)…
... 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 ... Normally (part of) the upper 32K simply wouldn't be ... you have maximum number of upper 32K chips inserted & ... x 8 bit static RAM chip for upper 32K (soldered on ...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)…
... the ROM tests the RAM when it boots.[/QUOTE]< ... think, just good enough that RAM chips which are [I] ... starters. There are some RAM test programs in the archive ... hold off or the static ram IC.[/QUOTE]
64Kx1 ... /> Btw: the SRAM for upper 32K isn't [I]exactly ...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…
... 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, ...New platform game: Sid SpannersHi all, here is my Christmas present. A new platform game (well, more of a mini-game really). [url=http://java.cms.livjm.ac.uk/homepage/staff/cmspc…
... creating more levels when the RAM filled up.
Yesterday ... a 25-byte gap in upper memory (in the SP1 library ...
