Posted By
MCes
on 2023-02-17
06:55:27
 |  Looking for specific 16k ram expansion cartridge
My technical curiosity leads me to look for a specific 16k ram expansion on cartridge that (internally) is like as these types:
16K Expansion Kingsoft
C16 RAM Pack
I would be interested in obtaining the physical object for analyzing it.
Does anyone have it or can help me find it?
Thanks!
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Posted By
javierglez
on 2023-03-06
12:20:49
| Re: Looking for specific 16k ram expansion cartridge
For a few years I was quite active on eBay as a buyer and I don't recall seeing any C16 memory expansion.
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Posted By
MMS
on 2023-03-06
18:38:21
 | Re: Looking for specific 16k ram expansion cartridge
Few years ago I saw one Hungarian 64k expansion card with a German C16 on ebay, but it was togethwr, not separately. But it was not the Kingsoft one MCes looking for
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Posted By
MCes
on 2023-03-08
10:02:05
| Re: Looking for specific 16k ram expansion cartridge
Thanks a lot guys for your interest.
I understood the basic way that is used for disabling the C16 internal RAM bank but I'm curious about how the expansion cartridges extract the exact /CAS timing information,
especially the cartridge (+16k RAM expansion) that produce this memory map:
$0000-3FFF original C16 internal RAM
$4000-7FFF cartridge expansion RAM
$8000-FFFF ?????? (mirrors?)
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Posted By
MMS
on 2023-03-09
15:44:54
| Re: Looking for specific 16k ram expansion cartridge
@MCes
Sorry for the question, I know you know the machine inside out, but the Expansion port has both RAS(D) and CAS(11) signals. Maybe my memory is not the best, but why getting CAS information is a problem?
OFF
Also, it i interesting to see, that the C16 PSU was sooo weak to do the task.
Nominal rating was 800mA, and the fuse was 1.0A. Based on the 1986 measurement, if you FFWD the tape, the C16 already took 1.06A, so it is quite high VS the PSU capabilities. It's a miracle they worked so long.
Then the memory expansion came, and not a big surprise my PSU gave up 2 times.
That's why I told beforehand, that the ZX Spectrum 2+ Grey PSU is the best for the C16. Same connector,voltage and polarity and 2.1A. (although early ZX Spectrums were supplied with rated 800mA PSUs with only 700mA, so ANY connected cartridge or expasion card caused a Kaputt
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Posted By
BSZ
on 2023-03-09
16:49:50
| Re: Looking for specific 16k ram expansion cartridge
@MCes: Yes, the $0000..$7FFF RAM memory is mirrored in the upper area. This is the only way to BASIC+KERNAL can work.
But... I had no such card in my hand, but I have met someone who has seen it.  Which in my opinion was one of the biggest mistakes in the history of the C264 family: for business reasons, CBM did not allow the memory expansion of the C16/C116 machines. Because of this, these expansion cards have to do some dirty tricks to work: the card overloads certain lines of the TED and/or CPU to operate. The result is questionable: some people have used them for a long time without failure, some not, but I wouldn't put almost 40-year-old chips under that kind of stress. That's why I think you shouldn't make an extension in this way, you don't need more dead TED/CPUs.
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Posted By
MMS
on 2023-03-09
17:19:50
| Re: Looking for specific 16k ram expansion cartridge
@BSZ
"for business reasons, CBM did not allow the memory expansion of the C16/C116 machines"
but at the same time made the Plus/4 unexpandable too. Compared to Sinclair QL (could be expanded to 640KB) it was a mere deep mistake of the post Tramiel management (though at that time the hardware project was definitely finished, including the NC signal called R/E initial drawings (RAM enable?).
Kind of funny to see, that you cannot do a simple memory expansion on the port called "memory expansion".
Should we ask Bil about this strange thing?
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Posted By
seff
on 2023-03-10
13:52:14
 | Re: Looking for specific 16k ram expansion cartridge
@MMS spot on. It was a grave mistake to introduce non-expandable C16 (by that I mean that CBM could have easily 'copied' ZX Spectrum's memory upgrade kit). I fully agree that the memory expansion port should have been 'open' to RAM expansion, possibly to 256 kB.
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Posted By
MMS
on 2023-03-10
16:18:38
| Re: Looking for specific 16k ram expansion cartridge
@seff 100% accurate, thanks
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Posted By
BSZ
on 2023-03-10
16:45:50
| Re: Looking for specific 16k ram expansion cartridge
@MMS: Yes, the original plans included external control of RAM. But I have a guess, the 64K version would not have included this. More complex cards with more memory could only have been made for the 16K version.  But that doesn't matter now, unfortunately.
The name "memory expansion" is correct, by the way: they didn't say what kind of memory. It's good for ROM!  (Perhaps a plain "expansion" or "expansion connector" would be more appropriate instead.)
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Posted By
SukkoPera
on 2023-03-10
17:04:56
| Re: Looking for specific 16k ram expansion cartridge
The point is that without the ability to extend the RAM, what use are the /RAS, /CAS and MUX signals on the expansion connector? At least MUX is useful for SIDcards, but I doubt that was in Commodore's intentions  .
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Posted By
MIK
on 2023-03-10
17:53:04
 | Re: Looking for specific 16k ram expansion cartridge
Just to add...
The C16 16k RAM Pack listed under the hardware section, the board next to the black case image is my one and it runs fine with the original CBM C16 PSU which includes either datasette or sd2iec attached. Treasure Island runs fine on the old brick. Maybe I'm sucking the guts out of the PSU but on the rare occasion I use it it works.
Retroscener if he still has it imported from Hungary a 64k ram pack for his C16 and it was just plug and play.
From memory there are two C16 rev.A models out there and neither work with a 64K ram pack without some hot wiring to get it working. However I was lead to believe rev.B C16's were fixed??? If Retroscener's 64k ram pack truly is plug and play then chances are it's a rev.B mother board.
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Posted By
MMS
on 2023-03-11
13:37:53
| Re: Looking for specific 16k ram expansion cartridge
OFF
@MIK yeah, a 32KB C16 / C116 would have been a GREAT difference from game development point of view. When you have the basic gfx elements and music in the memory, with extra 16KB you can add a lot of extra places, more story, more depth.
It is very evident on ZX Spectrum too, that the 16KB games (even the classic ones) are very simple games compared to the later 48KB games. (though 6502 code is more compact in most of the cases)
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Posted By
MIK
on 2023-03-12
23:51:57
| Re: Looking for specific 16k ram expansion cartridge
OFF TOPIC:
@MMS If you get time and I mean a number of hours..., and be warned as you might get sucked in the deeper you dig the Acorn Electron is an interesting one. It 'has' 32K. What's more it was held back from it's full commercial potential thanks to the BBC Micro, something we kind of share having the C16 or Plus/4 next to the C64.
What is also mad, if anything used colour on the Electron it would eat the memory big time so on average there may of only been 16k of memory left to play with. Many of it's games come in the 4 colour flavour.
and to share a link: http://www.acornelectron.co.uk/
Take a look at the software houses list on the left and take your pick. Try TYNESOFT for example.
The guy that created/runs the site can come across as a bit crazy and even funny at times when he slates a bad game in his "5 games in 5mins video's" but there is a lot of stuff to nose at and a good number of games were also released on C16/Plus4, like Phantom, Thrust, Cops N' Robbers, Blagger and many more. In many cases I think the C16 comes across as better but it's still neat to check out, some cool games for sure that we never got as well.
I started to have a nose at the Electron just before xmas and ended up staying up half the night. I found it fascinating, addictive even.
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Posted By
Ulysses777
on 2023-03-13
19:58:29
| Re: Looking for specific 16k ram expansion cartridge
For what it's worth, I've had a go at making a schematic of the Stonechip RAM expansion, hopefully it's correct:
stonechip16k
And here's a picture of the other side of the card (which I took in 2005 and forgot about it  )
stonechip_c16_ram_back
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Posted By
MCes
on 2023-03-15
05:17:27
| Re: Looking for specific 16k ram expansion cartridge
@Ulysses777
Thanks for the info,
now the strategy of the circuit is (almost) readable.
I doubt that the capacitor connected to the 1N4148 diode is only 10pF, do you have a pic that makes its labels readable?
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Posted By
Ulysses777
on 2023-03-15
09:07:16
| Re: Looking for specific 16k ram expansion cartridge
@MCes
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Posted By
MCes
on 2023-03-20
13:04:27
| Re: Looking for specific 16k ram expansion cartridge
@MMS wrote:
"(...)the Expansion port has both RAS(D) and CAS(11) signals. (...) why getting CAS information is a problem?"
The problem is that the /CAS cartridge line is the same line that is connected to internal Dynamic RAM chips, so if you disable the D-Ram /CAS you also lose the /CAS signal on cartridge....
@Ulysses777: Thanks a lot for your informations!
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Posted By
MMS
on 2023-03-21
03:08:42
| Re: Looking for specific 16k ram expansion cartridge
@MCes: thanks for the info
OFF
@MIK: BBC Electron Yeah, those attribute free gfx modes are quite interesting with high resolution, they could create new colors with smart mixing, like on EGA. But 8 colors only. Eh...
Still I found a lof of gfx shown there quite fancy.
The drawing on the screen is similar to our Scale command I really hated what a useless feature. And it was the only way on Electron.
Anyhow, one thing I really admit: Electron had a real 640 pixel wide resolution, and a 80 char wide txt screen. Without this resolution no nice GUI or the use as a serious word processor is possible. 640x200 resolution needs 16KB RAM even without attribute, so it could not fit into C16 (though they could let only the Plus/4 users use this feature).
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Posted By
MMS
on 2023-06-11
18:31:59
| Re: Looking for specific 16k ram expansion cartridge
Wow, it is more valuable than it was as a new one. At least it exists and may be useful for someone.
BTW I remember someone copied a scanned verion of a Hungarian 64K expansion, and in the Instructions For Use they told how to cut two tracks on the C16 motherboard to get the 64K module working. Well, it is noz the classic "plug and play" method
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Posted By
MIK
on 2023-06-11
20:40:36
| Re: Looking for specific 16k ram expansion cartridge
Looks like the same type as the one Retroscener has or had which I believe he imported from Hungary.
I'm surprised it doesn't come with it's own power supply seeing how long it is.
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Posted By
javierglez
on 2023-06-13
10:43:46
| Re: Looking for specific 16k ram expansion cartridge
Price decreased to $99. Still not interested since MCES said it will eventually crush the TED.
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Posted By
MCes
on 2023-06-16
01:59:31
| Re: Looking for specific 16k ram expansion cartridge
@javierglez
I'm reconsidering whether forcing memory out is bad for TED,
certainly it is an improper use of the signals, but in electronics forcing a pin of the chip is considered possible.
I am convinced that to kill the TED and the CPU is mainly the electric discharges that reach the chip from the JOY port and from the TAPE/DISK port
(my solution for the C16 is the "JUGGLER" which doesn't put the CPU or TED in direct communication with the ports, protecting the chips)
So to expand the C16 I recommend the internal modification as a first solution but I don't demonize the external cartridge ....
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Posted By
MMS
on 2023-06-16
15:58:50
| Re: Looking for specific 16k ram expansion cartridge
@MCes thanks for the clarification. I will use serious ESD protocols before I will touch my Commodore the best way is to grab a radiator beforehand.
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Posted By
HiFi of TLT
on 2023-06-18
09:49:39
| Re: Looking for specific 16k ram expansion cartridge
Helló,helló Újra Itt vagyok..... MCes: Végre ismét JÓL beszóltál a JOY és TAPE vezérlés híbájairól,és persze az ESD védelemről! Ezt UGATOM már vagy 30-harminc éve!!! Az 1996-ban tervezett SID kártyánál (BSZ of NST-HiFi of TLT) ép ezért volt a vonal szétválasztás és persze erősítés is. Ezúttal KÖSZÖNÖM,ismét,BSZ-nek a segítséget! Persze hozzá terveztem a 12V-9V-os IC-s kapcsolóüzemű tápot a különböző SID-IC-hez és az órajel generátort,két oldalas nyákot! MMS: így IGAZ,a hűtőbordák csak javítják a chip belső hőmérsékletét,főleg a C16-ban a TED-CPU-hoz,a C117-ben úgy szinten! A PLUS/4-nél a TED már egy fém árnyékoló ill. hűtésre is alkalmas kalitkában van. 45 év után (2020-07-17) mentem nyugdíjban a félvezető és elektromos iparból (Egyesült-IZZÓ-TUNGSRAM-MEV-VISHAY-STANLEY-BOSCH)! MI még a '70-es évek végén a PIPIS-hegyen (Gyöngyös-TUNGSRAM) növesztettük a germánium egykristályt a laborban a diódák és tranzisztorok készítéséhez (OA-AC-AF-AD-diódák és tranzisztorok). Egyik félvezető sem szereti a nagy hőfokokat,hísz megváltozhat a kristályszerkezetük (NANO-technilógia!). DE én is azt javasolom (nem egy pár C16-C117-et átalakítottam 64K-RAM-mal), hogy az eredeti nyákon kell megvalósítani (persze IC foglalatban). Ha valakinek kellene 64k-RAM,szívesen adok ,van még néhány a tarsolyomban. Üdv.: HiFi of TLT
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Posted By
javierglez
on 2023-06-18
14:16:20
| Re: Looking for specific 16k ram expansion cartridge
I entered the previous message in google translator (I think the translation is good)
Hello, hello, I'm here again..... MCes: Finally, you spoke GOOD again about the faults of the JOY and TAPE controls, and of course about the ESD protection! I have BEGGED this for about 30-30 years!!! The SID card designed in 1996 (BSZ of NST-HiFi of TLT) had line separation and of course amplification for this very reason. This time, THANK YOU again to BSZ for the help! Of course, I also designed the 12V-9V IC switching power supply for the various SID-ICs and the clock signal generator, double-sided board! MMS: so TRUE, the heatsinks only improve the internal temperature of the chip, especially in the C16 for the TED-CPU, in the C117 at the same level! At PLUS/4, the TED is already a metal shade or it is in a cage suitable for cooling. After 45 years (2020-07-17) I retired from the semiconductor and electrical industry (Egyesült-IZZÓ-TUNGSRAM-MEV-VISHAY-STANLEY-BOSCH)! At the end of the 70s, WE grew germanium single crystals in the lab on the PIPIS mountain (Gyöngyös-TUNGSRAM) for the production of diodes and transistors (OA-AC-AF-AD diodes and transistors). None of the semiconductors like high temperatures, because their crystal structure can change (NANO technology!). BUT I also recommend (I have not converted a pair of C16-C117 with 64K-RAM) that it should be implemented on the original board (of course in an IC socket). If anyone needs 64k RAM, I'll be happy to give it to you, I have a few more in my bag. Regards: HiFi of PTO
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