Questions tagged [ram]

For questions about Random Access Memory

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How can I resolve these intermittent memory issues?

I own a 1999 IBM Personal Computer 300GL (Type 6275-90U). It's a Slot 1 Pentium III, Intel 440BX chipset, with a riser board for adding PCI and ISA cards and 3 PC100 DIMM memory sockets. About 50% of ...
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8 votes
2 answers
496 views

Could a Saturn 128K card be used as a /RAM device under ProDOS?

For starters, the Saturn 128K card was a RAM expansion card produced during the Apple ][+ era. From what I recall, unlike the later AUX slot RAM expansions for the Apple //e, it did not provide bank ...
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14 votes
3 answers
3k views

Release timeline for 128KB personal computers?

IBM, Apple, Commodore, and Atari all released upgraded versions of their popular home/personal computers having "stock" 128KB of RAM around the early 1980's. What was the order of release (...
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16 votes
1 answer
4k views

What kind of RAM stick is this?

Specifically, what are those two modules in the middle of each? I'm not too familiar with components this old. I've figured out that they're sticks of SEC SDRAM, but I've found nothing about any of ...
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10 votes
1 answer
287 views

How to find what is using Chip RAM?

My AmigaOS should have more Chip RAM available to use than it reports (only 800 kB). Is there a way to find what is sitting in Chip RAM and how to move it to Fast RAM instead?
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3 votes
1 answer
271 views

Can Alice be hacked to use more than 2MB Chip Ram

Is it possible to hack Amiga Alice chip and use more than 2MB CHIP RAM? It's a long shot, but I assume if it was possible someone would have done it already? The maximum amount of Chip RAM in any ...
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12 votes
1 answer
403 views

Amiga A1050 schematic

I’m trying to resurrect a Craigslist Amiga A1000. After replacing Paula it now boots. Several basics still missing (RF shields, screws, port covers, etc.) but essential electronics are okay. However, ...
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-7 votes
2 answers
339 views

Why do PlayStation 1 CD-based video games (nearly?) always have to reload the entire level each time you start over? [closed]

Billy Bob boots up Tomb Raider on his PlayStation. He loads the saved game from his memory card and it loads up the level he is on. Then Billy controls Lara in a sloppily manner, so that she dies. Now ...
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24 votes
4 answers
5k views

When did half-bad RAM chips stop being available?

The ZX Spectrum sold with either 16 or 48K RAM, necessitating an optional 32K memory bank which was achieved in a characteristically (for Sinclair) cleverly frugal way: with half-bad 64kbit DRAM chips,...
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5 votes
3 answers
381 views

Modern (cooler) replacements for vintage static RAM chips

The device I'm using (a SYM-1, probably c. 1979) has a stack of L2114-UCE 1024x4 static RAM chips ("2114 static, TTL in/out 1024x4 N-MOS RAM", the -UCE means "450ns access time, 315mW ...
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  • 417
4 votes
2 answers
715 views

How fast was Rambus compared to regular EDO RAM?

The Nintendo 64 used Rambus RDRAM. This was an unusual choice, e.g. the PlayStation used regular EDO RAM which I gather most consoles and computers did at the time. As I understand it, Nintendo chose ...
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3 votes
1 answer
320 views

How much RAM was sold each year in the 1970s?

I'm trying to get an idea of the quantitative parameters of the computer industry in the era that saw the rise of personal computers. Of course, the industry as a whole was old by then; companies like ...
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16 votes
2 answers
721 views

What process node were 4k and 16k DRAMs first made at?

In the history of computers, much is said of microprocessors, for good reason, but the relatively unsung RAM chips were equally important. Of particular significance were the 4kbit and 16kbit dynamic ...
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-1 votes
1 answer
162 views

Possible and impossible RAM layouts in 8086 [closed]

The Intel 8086 CPU could address up to 1 MB of memory using segmentation, and this CPU have 4 segment registers, which are CS and SS and DS and ES. Each segment in memory can have a maximum size of 64 ...
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5 votes
2 answers
629 views

CBM PET 2001 garbled screen

I picked up this PET and trying to restore it. Screen is garbeled on boot and stays like that displaying random chars, some of them flashing. Tried to resocket the chips, but it didn't help. I don't ...
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2 votes
2 answers
343 views

What is a 4002's "RAM Status Character"?

I was looking at this emulator of a Intel 4004, and I noticed something with the RAM. It had something called "Status Chars". There were 4 of them per memory line and all were 4-bit numbers ...
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  • 321
21 votes
8 answers
5k views

Which CPUs, if any, had an 8-bit address space?

Even the Intel 4004, which had a 4-bit word size, had a 12-bit address space. I'm wondering if any commercial CPUs had an 8-bit or similar address-space for programs, data, or both. I'm particularly ...
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  • 461
2 votes
3 answers
355 views

Why did IBM System 360 have byte addressable RAM

According to wiki IBM System 360 had byte addressable RAM. Previously IBM had machine with word addressable memory. Did they make a switch for comparability between different machines? Or it was just ...
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1 vote
2 answers
210 views

How much memory in this 1040STE system

What is the total size of 1040STE with 4 of these SIMMs installed? How to check the memory using software and which one?
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2 votes
1 answer
246 views

A1200 Amitek Hawk, Guru Meditation 8000 000B when loading games from Gotek

Hardware: A1200 CF 4GB (sys part 800MB) KS 3.1 40.68 ClassicWB Amitek Hawk 4MB, FPU 68882, oscillator 28MHz Gotek, Flash Floppy 2.1.4 When Amitek is used the machine boots from Gotek USB adf file ...
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6 votes
2 answers
306 views

Why was the maximum byte size of 8 bits on IBM 7030?

As far as I know, IBM 7030 used term byte. But this byte was just an imaginary term to make easier for our brain to work with bits. So it had nothing in common with a physical realization of the CPU. ...
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3 votes
2 answers
891 views

Why did IBM 7030 or IBM 360 use byte and word addressing simultaneously

In 1950s machines had a 36 bit words. And in this word we could pack symbols using 6 bits. And to fetch this symbols from the word programmer should do it using bit manipulations. In 1961 IBM released ...
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4 votes
1 answer
255 views

Back in the day, were games coded to run better with more (not faster) RAM? [closed]

Let's say the year is 1999 or something like that. I have a PC with 400 MHz, no graphics accelerator and 64 MB RAM, and try to run some Need for Speed game or something. I notice that it goes laggy. ...
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6 votes
2 answers
1k views

Is solder-on memory upgrade an option here and how to check it

I have this system with 2MB onboard RAM, but I noticed there are additional soldering pads to the right from memory chips (NEC 424400-80L, but there are also TOSHIBAs TC511664JL-10 on daughter board ...
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12 votes
3 answers
2k views

Decoding Logic and Memory Systems for 8-bit computer - 64K address space

I am creating a minimal Z80 computer with serial output on a breadboard. I have kind of moved up from the last question, where I was executing instructions on Z80 using specific connection of ...
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  • 533
2 votes
2 answers
434 views

How fast did the ARM-1 access memory?

The ARM-1, an early 32-bit RISC CPU, was used in the Acorn Archimedes computers, released in 1987. Its rated speed was one 32-bit instruction per cycle at 8 MHz. Typical RAM chips at that time would ...
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2 votes
1 answer
454 views

What was the last of the Thinkpad X series with replaceable RAM? [closed]

I know my x230 has replaceable RAM. I know the x395 lists its ram as being soldered. What is the last of the X series lineup with user-serviceable RAM?
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  • 3,118
14 votes
4 answers
3k views

Why did 1-bit DRAM chips have separate data input and output?

Many 1-bit DRAM chips provide two pins for data communication, one for writing data (typically described as Din or D on datasheets) and one for reading data (Dout or Q). Examples I've found include ...
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  • 7,564
5 votes
1 answer
387 views

What is the largest RAM expansion for Amiga or Commodore? [closed]

What is the largest RAM expansion being manufactured today for Amiga and Commodore 8-bit?
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4 votes
1 answer
488 views

How wide were the RAM chips in the PlayStation 1?

In earlier years, it was common for DRAM chips to be one bit wide, so that an 8-bit machine would use eight of them to form one memory bank. Occasionally, 4-bit-wide chips would be used, e.g. the ...
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10 votes
3 answers
1k views

Cost of dynamic versus static RAM in the early days

Early pioneers building memory cards for personal computers, tended to use static RAM, because it's quite a bit easier to get to work. Later, dynamic RAM became de rigueur, for the simple and ...
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  • 48.8k
0 votes
2 answers
783 views

Get himem.sys working on an AMI 1.06.09 bios (not on VM)

I tried many 98SE boot disks online, they all boot successfully on my mobile workstation from USB (C:\>), but all can't run the Windows 98SE Installer because of XMS Memory, giving an error like: ...
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3 votes
1 answer
196 views

How long would a 41256 take to do 4 accesses in fast page mode?

I have been surprised at how little use eighties computers made of fast page mode access to RAM. (A notable exception being the Sinclair Spectrum, which used it to get the necessary bandwidth to video ...
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4 votes
3 answers
550 views

What was stored in memory that was "unavailable to BASIC"?

On home / personal computers (such as before 1984), a machine might be described as having 24k RAM, but only 18k of that available to BASIC. If the machine had BASIC and the OS (or BIOS) stored in ROM,...
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9 votes
3 answers
622 views

what is DMA and how does it work?

I've heard the term 'DMA' being used a lot in reference to older consoles. My very basic understanding is that it's a way for the console to access memory directly. But directly as apposed to what? ...
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7 votes
2 answers
545 views

Is it safe for C64 cartridges to respond to read and/or write requests on "unmapped" addresses?

According to the C64 wiki, asserting G̅A̅M̅E̅ on the cartridge port (and not asserting E̅X̅R̅O̅M̅) of the C64 leaves three blocks of the C64 address space "unmapped": 28 KB @ $1000 (otherwise RAM), 8 ...
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  • 20k
11 votes
3 answers
2k views

Small RAM 4 KB on the early Apple II?

Most of the reference material for the Apple II that I have seen refers to the 4116 RAM chip which held 16x1 kbit. This provided 16, 32 or 48 KB in banks of 8 chips. The Apple II motherboard layout ...
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  • 9,396
13 votes
2 answers
704 views

Atari ST DRAM timing puzzle

From the Atari SM124 Monochrome Monitor Service Manual, I get that the video signal timing for one line is 20µs. With the horizontal resolution of 640 pixels, this gives a 31.25ns pixel clock. Using ...
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  • 815
11 votes
1 answer
3k views

3 beeps on a 486 computer with an American Megatrends bios?

So far I've figured out that means something about the ram bit I haven't been able to figure out what the problem is Edit: video link
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4 votes
1 answer
524 views

Was there any VIC-20 expansion to bring memory beyond the default maximum of 40 KiB?

The Commodore 64 was very flexible in terms of how RAM could be controlled. ROMs and I/O devices could easily be swapped out by setting bits in the first two addresses of memory. The VIC-20's ROMs and ...
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  • 466
6 votes
1 answer
324 views

The IBM RAM with non-standard pin layout

One and half decade ago I had an black IBM Thinkcentre tower. The specs were: Pentium 4 2.66 GHz 256 Mb IBM RAM (which later got upgraded into 512 Mb RAM), 40GB HDD, XP Pro SP3, GeForce 2 MX 400. ...
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2 votes
2 answers
600 views

Parity error under DOS

I'm facing a Parity Error problem on my new 486er DOS Retro PC. Every now and then, a running software crashes with a Parity Error output on screen. This happens for different software so I think the ...
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  • 278
9 votes
1 answer
373 views

Patch BBC Master ROM using Sideways RAM?

I have a BBC Master 128 with the standard ROM installed. This includes ADFS v1.50 in slot "D". I want to replace this ADFS in ROM with a patched version, loaded from disk, into Sideways RAM. It is a ...
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  • 56.5k
6 votes
3 answers
2k views

Why are RAM chips 1 or 4 bits wide?

I don't know whether it's still the case, but at least in the early days, it was common for RAM chips to be one bit wide, so e.g. an 8-bit computer would install them in groups of eight. I gather at ...
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  • 48.8k
9 votes
1 answer
775 views

Commodore Plus/4 60671 bytes free - how?

It is widely known that, while the Commodore 64 did indeed provide 64K of RAM for machine code programs, only 38K was usable from BASIC; this was because bank switching was needed to get at the rest, ...
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  • 48.8k
12 votes
2 answers
2k views

Why was BASIC on the Commodore 64 one byte shy of 38KiB?

When you power up a Commodore 64 you are greeted with a friendly message telling the user it has 38911 BASIC bytes free. 38,911 is one byte shy of a 38 KiB (1,024 * 38 = 38,912). What was the reason ...
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1 vote
1 answer
185 views

Does the TurboGrafX16 store switches and/or flags in RAM?

Based the the specs I found for the TG16, it has 8 KB of RAM. I also found notes in the documentation of many opcodes that there is data stored in several "flags and switches" are these stored in RAM ...
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20 votes
2 answers
3k views

Why does the VIC-20 have 5KiB of RAM?

Why does the VIC-20 have 5 KiB of RAM? Why not a multiple of 4 as any other systems, e.g 4 KiB or 8 KiB. Is there a technical reason for that?
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