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1 Meg Super AMS Discussion Thread


Omega-TI

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I think I'm the same way. It looks very pretty. But what exactly does it do? Does it replace the 32 KB expansion board? Or is it used in concert with it? Are there code samples around that demonstrate how an assembly language programmer might do something with it? Do any parts of the memory persist upon loss of power? etc.

 

I have been considering the way I would like to use SAMS memory in assembly applications. One way would be to have a memory manager that you could ask to allocate a chunk of memory. You would get some kind of handle back that you would use when calling functions to read and write the allocated memory. Another approach would be to treat SAMS memory as one big memory space with 20-bit addressing controlled by the application. You would have functions to copy data back and forth between SAMS memory, CPU memory and VDP memory. In the attached I have been working on some functions for the latter, plus a detection function, and there is a short test at the beginning. Note that I'm using R10 as stack pointer and that charset.a99 just contains a character set.

SAMS.a99

charset.a99

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Ksarul,

 

For those of us building boards, I'd like a recommendation on a IC logic tester that can test the 74LS612N? The eprom programmer I have, the TL866 MiniPro, does some IC logic testing, but it doesn't cover that chip, and lacks coverage of a few others.

 

Any advice would be Awesome!

-M@

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I tested the ones I have with a Topwin 3000. It seems to have all of the 74-series chips I wanted to test so far in its dropdown menu. It isn't an expensive programmer either--and it has the bonus of being able to program the 16-bit chips used on the Yellow boards too. . .

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Chips on this board that the minipro TL866CS will not test are:

555
74LS6838
74LS612

I am almost done building my board, just waiting on a heatsink for the voltage regulator, and the Topwin to test my 612s.

Since it is a 1 meg board, instead of headers and jumpers, I'm just soldering in trimmed off leads from the capacitors. Saving my jumpers for cart boards :)

In case anyone else has trouble reading one of the labels... The board labeling for the 74LS04 (next to the 74LS612) has the zero cut off just perfectly so it looks like it says "74LS34". I wouldn't have noticed except I double checked it all against the picture Omega took over in the PNW Fest West thread:

http://atariage.com/forums/topic/248617-pnw-ti-994a-fest-west-2016-april-30th/?p=3488028

Nice zoomed in picture! You can tell it isn't a 3 printed on the pcboard if you compare against the 3 in the 74LS683 labeling for the chip below it. These little print defects from the pcboard printers are not necessarily consistent. So it might just be me.

Other than that little eyesight problem, the board is very almost self explanatory to build.

 

-M@

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BTW, that is not a 683--it is a 688. . .the board mask mangled the last 8 due to its location over a via. . .

 

Ah, back to ebay then... My earlier post has been edited so I don't mislead anyone. The 3 that is supposed to be an 8 still looks more like a 3 than the cut off 0 with it's diagonal in the font.

 

Lets check the rest now ( I no longer trust my ability to read ):

 

5x 0.1uf tantalum capacitors

1x 47uf electrolytic capacitor

1x 100uf electrolytic capacitor

1x 220 ohms resistor ( I'm assuming a 1/4watt will do for both resisters )

1x 22uf tantalum capacitor

1x 1k ohm resistor

1x 7805 voltage regulator

1x heat sink for voltage regulator

1x LED

 

1x 74LS125 Quad bus buffer ic

1x 74LS138 3 line to 8 line decoder ic

1x 74LS32 Quad 2-input OR gate ic

1x 74LS04 Hex inverter ic

1x 74LS612 memory mapper ic

2x 62512 SRAM ic

 

1x 74LS259 8 bit addressable latch ic

1x 74LS08 Quad 2-input AND gate ic

3x 74LS244 Non Inverting Buffer/Driver ic

1x 74LS688 8 bit magnitude/identity comparator ic ( Noted alternative: 25LS2521 )

1x 74LS245 Octal Bus Transceiver ic

1x 555 timer ic

1x 8pin dip socket ( 2x4 )
1x 40pin dip socket ( 2x40 )
2x 32pin dip socket ( 2x16 )
4x 14pin dip socket ( 2x7 )
2x 16pin dip socket ( 2x8 )
5x 20pin dip socket ( 2x10 )

 

and a bit of thermal compound for the heat sink.

 

Is this correct?

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You have all components properly identified now, and yes, 1/4 Watt resistors are the correct size. I also attached a nice drawing of the top of the board showing what components go where to this message. I've put it up before, but it really belongs here too.

post-27541-0-90045400-1462656279_thumb.png

Edited by Ksarul
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IIRC, Art Green's assembler/linker package handled the memory mapping functions of the SAMS. Brad Snyder's XB Packer used the 128 Meg board to store 4 different XB environments -- or something like that.

 

In my inventory of IC's, I show 4 of the 74LS612 memory mappers, not including the one on my 286 XT that I keep for running MFM hard drive diagnostics. Is the '612 hard to find? It probably is at my house, but I know the 1000 cubic foot area where the 4 reside. I have not needed the '612 in 20-odd years, and I will not waste my time looking for them if they are easily obtained, but I will donate them to the project if I find them.

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I actually have about 100 of them from a recent purchase which I'll be testing out for this batch of boards. They are not too difficult to find, but it is hard to find them for prices below $5 (ignoring Chinese sources, as chips from there can be a real crapshoot when it comes to operating like they are supposed to--assuming the chip inside the package is even what it purports to be, which is also a questionable proposition). I'm about ready to put chips into a dozen newly-assembled boards (that won't happen until next weekend, as She-Who-Must-Be-Obeyed must be propitiated tomorrow), so I'll have them ready for the folks who registered initial interest in them sometime next weekend.

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JediMatt: You're welcome to use my logic analyzer anytime you want it. It's a Gould K205 and I do have cables and pods for it, as well as its manual. I haven't used it much, but it's a capable little box. It was 50% off on "black Friday" a couple of years ago at Surplus Gizmos. It had a RAM error during POST which went away when I reseated all the RAM in it.

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Yours went into the mail yesterday, Chris. I'll be notifying a number of people later today that their cards are also ready (including yours, Omega). I've been running the first eight cards through some comprehensive stress tests today. . .I'll have a bunch more ready when my RAM chips arrive sometime within the next few days (I realized when I started populating the sockets for the 12 boards that are physically ready to go that I only had enough memory to populate the first eight of them--Doh!). I thought I had one more tube of memory chips than I actually had, so I had to get a quick parts order in. Now I have enough of all parts to build at least 25 more boards (once the memory arrives). . .after that, I'll have to order some more bare boards. They will remain available indefinitely, as I try to keep the boards I release in stock permanently when the need is obvious (and I release the Gerbers for the few boards that I don't keep available, as that lets others make those if there is ever additional need for them).

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I'll be notifying a number of people later today that their cards are also ready (including yours, Omega).

 

Yesssssssssssssssssssssssssssssssss!

Already got the PM and PayPal'ed the money! I'm looking forward to plugging it in! Thanks again.

Seriously, I don't know what this community would do without people like you to feed our addiction. :-D

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Serial # 0005 arrived today. The red light is already blinking away -- Jim you are the MAN!

 

Now.. what would a post be form me without a dumb question or two:

 

1.) I noticed two jumpers (J1 and J2) which each have three pins. These seem to be jumpered on the 512K side. Do I want to move this to 2048 side on one or both or?

 

2.) Any recommendations on awesome stuff to do???

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Serial # 0005 arrived today. The red light is already blinking away -- Jim you are the MAN!

 

Now.. what would a post be form me without a dumb question or two:

 

1.) I noticed two jumpers (J1 and J2) which each have three pins. These seem to be jumpered on the 512K side. Do I want to move this to 2048 side on one or both or?

 

2.) Any recommendations on awesome stuff to do???

 

1 pretty sure you have a 1024k board, so you'd want to leave them there.. the 4096 part doesn't work yet on this revision

2 there's a topic for that: http://atariage.com/forums/topic/239531-amssams-software-list/

 

Greg

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So... Has anyone tested this with TIMXT or Stuarts IB? I am freezing my machine. It isn't locking up but with the BBS it loads about half the login page and stops. With SIB I'm having to reload pages and eventually nothing will load. Not sure if the ram expansion card is correlated, I'll try resetting my crappy cable modem and try again.

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I've not tested it with either of those programs, but they should see it as a standard 32K card.

All is well so far. A little slow but that could definitely be my IC. I will continue to monkey around with this new awesome piece of hardware.

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