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Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Sun Dec 08, 2019 4:29 am
by MCes
eslapion wrote: Sun Dec 08, 2019 3:57 am I will kindly ask you to refrain from posting in the threads related to my products, as I do with yours.
Yes,
excuse me but I was victim of my technical curiosity,
and now that the V1.4 SARUMAN-TED pass the DIAG 264 tests there are not reasons to speaking about it ...

I have "reduced" my previous post because it was not intended for injure your project, but it could be misunderstood.
Ok, now I'll try to be silent....

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Mon Dec 09, 2019 6:52 am
by eslapion
Technical detail: This product, like other SaRuMan products, consumes only 5mA of power.

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Wed Dec 11, 2019 5:29 pm
by eslapion
Just played Slipstream on C16 for the very first time. Most impressive.

https://psytronik.itch.io/slipstream

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Fri Dec 13, 2019 6:33 am
by eslapion
With DIAG264...
DSC03239.JPG
DSC03249.JPG
DSC03272.JPG

The handmade prototype of SaRuMan-TED:
DSC03237.JPG

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Tue Dec 17, 2019 11:32 am
by MCes
Ok, now that you have updated the schematic of V1.4 (now V1.5?) I have no more perplessity about its wellworking,
but I noticed that this patch is done with another gate located into a "single gate chip",
but all it can be done in a more elegant way with a single 74 chip.
I wrote a "pizzino" (see pic) with a possible solution, it's a theoretical schematic but it should work at first shot...

I hope this post will be welcomed.
MCes1.JPG
This solution is based on double decoder '139,
with its A0 input the "Y" half selects which output (Dynamic or Static) will be driven by /CAS-TED signal,
so the switch will select the S-64k or D-16k ram bank.
The second half "X" is used as "LUT" and its /Q0 will be "L" only if the CLK are "L" during a Write cycle,
it will deselect the S-Ram lowering the ram input CS2 (that is active H).
So the "X" half will limit the CAS time to the falling edge of the CLOCK but only during a write cycle.

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Tue Dec 17, 2019 7:24 pm
by eslapion
MCes wrote: Tue Dec 17, 2019 11:32 am I hope this post will be welcomed.
If you see a problem and have a solution to offer, the information is always welcome.

Unless of course, you see a problem and honestly don't know of a solution, you can always mention it too.
but I noticed that this patch is done with another gate located into a "single gate chip",

This solution is based on double decoder '139,
I do see a problem with your solution; both outputs (!Q0 and !Q1) from the second (Y) selector will require pull-up resistors*. Otherwise, this solution seems good. However, I get my PCBs made and populated in China. They only offer CMOS logic ICs and have no 74HCT139 or 74AHCT139 in stock. 74LS139 is not available.

Stock 0 ... https://jlcpcb.com/quote#/parts/compone ... t=74HCT139

Even if they did, the price for a 74HCT139 in SOIC (they don't carry TSSOP) is $0.2450 while a TSSOP HCT00 is $0.1189 and the single gate 74AHCT1G32 is $0.0624 so the price for my present solution is $0.1813 which remains less expensive.

* a solution is to swap your connections of GND to !E and !CASTED to A1.

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Wed Dec 18, 2019 1:07 am
by MCes
eslapion wrote: Tue Dec 17, 2019 7:24 pm I do see a problem with your solution; both outputs (!Q0 and !Q1) from the second (Y) selector will require pull-up resistors
It don't need any pull up resistors, "H" on /E input doesn't drive in high impedance the outputs,
but simply it will deselect all of them (deselected line= "H" levels, not 3state..)

http://www.ti.com/lit/gpn/sn74ls139a

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Wed Dec 18, 2019 5:29 am
by eslapion
MCes wrote: Wed Dec 18, 2019 1:07 am It don't need any pull up resistors, "H" on /E input doesn't drive in high impedance the outputs,
but simply it will deselect all of them (deselected line= "H" levels, not 3state..)
Correct... that tells you how often I use demuxers... I also avoid TTL-LS ICs because they're not available in TSSOP format.

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Sat Dec 28, 2019 4:31 pm
by eslapion
The new V1.4 boards have arrived in good condition. A few of them were tested and all is OK now.

The new units begin shipping on Monday.

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Sat Jan 11, 2020 5:54 am
by eslapion
The version with NO SWITCH (64k all the time) is 13.50$US or 12 Euros per unit + shipping.

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Thu Apr 23, 2020 11:35 am
by emilen72
Hi, Do you stil offer the V1.2 for free?
Thanks
eslapion wrote: Wed Dec 04, 2019 6:00 am
MCes wrote: Wed Dec 04, 2019 5:26 am
eslapion wrote: Wed Dec 04, 2019 5:24 am
Actually it does now.

There was an error on PCB v1.2 and everyone who got that version got a refund. PCB V1.4 is in production.

Since the people who got V1.2 were refunded AND there is a fix, the people who do the fix get a free 64k RAM expansion for their C16.
Thanks!
At your service.

Since my little Chinese friends left me stuck with more than 20 PCBs of V1.2, they are free to a good home. Would you be interested in a few ?

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Fri Apr 24, 2020 9:59 am
by eslapion
emilen72 wrote: Thu Apr 23, 2020 11:35 am Hi, Do you stil offer the V1.2 for free?
Thanks
Sure. Just pay for postage.

Any reason why you'd want faulty PCBs ? Want to make a bunch of key chains ?

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Mon Jan 25, 2021 3:15 pm
by Hubi
Hi,

I'm interested in two SaRuMan-TEDs, one with and one without a switch, shipping to Germany. Could you please PM me for further details?

Re: SaRuMan-TED 64k RAM for C16 and C116

Posted: Mon Jan 25, 2021 11:49 pm
by orion70
Hi there, Eslapion is not in this forum anymore.

See HERE.