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Author Topic: Internal memory expansion plus USB (Read 16886 times)

Offline elmer

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Internal memory expansion plus USB
« on: 2021.March.02. 21:06:19 »
JLCPCB, the manufacturer that made my 512KB internal memory expansion board, has expanded the list of components that they offer, and can now also install USB connectors.

This has created the possibility of designing something that I would personally like to have ... an internal 1M byte memory expansion board, together with a USB port so that the Enterprise has a fast path to communicate with a PC, or perhaps a Raspberry Pi.

The FT245RL USB chip that I am thinking of using is very simple to interface with on the Enterprise side, and needs no complicated USB software to be written. All of the really difficult stuff is handled by the chip itself, and by the PC drivers that the manufacturer provides for free.

One of the friends who provided me advice on my previous board is already using the FT245RL in a new design that he is working on, and so I am lucky enough to have his experience to help me with an Enterprise board design.


The obvious use for the USB connection would be to quickly transfer files between the Enterprise and a PC, without the need to swap SD cards.

Although the FT245RL can transfer 1M bytes per second, experience on other 1980s computers has shown that we are more likely to get 50-100K bytes per second on the Enterprise.


The board layout (3" x 1.75") is nearly finished, and so I am thinking about how many to order.

If this works, and is affordable (approx $30 USD  or 10,000 HUF), would anyone be interested in a board like this?


One more thing ... since this uses a GAL for the memory decoding, I hope that it should coexist happily with the Symbiface3, EPNET and other existing Enterprise expansion boards.

I am currently planning to use segments C0h-FBh, and either B8h-BFh or 78h-7Fh.  Can anyone see any problems with that?

====================================================================

A JLCPCB, az 512 KB-os belső memória bővítőkártyámat gyártó gyártó kibővítette az általuk kínált alkatrészek listáját, és most USB-csatlakozókat is telepíthet.

Ez megteremtette a lehetőséget egy olyan dolog megtervezésére, amelyet személy szerint szeretnék ... egy belső 1 M bájtos memóriabővítő kártyát, egy USB-porttal együtt, hogy az Enterprise gyors utat tudjon elérni a PC-vel, esetleg egy Raspberry Pi-vel való kommunikációhoz. .

Az FT245RL USB chip, amire gondolok, nagyon egyszerűen kezelhető az Enterprise oldalon, és nem kell bonyolult USB szoftvert írni. Az összes nagyon nehéz dolgot maga a chip kezeli, és a PC-illesztőprogramok, amelyeket a gyártó ingyen biztosít.

Az egyik barát, aki tanácsot adott nekem az előző táblámon, már használja az FT245RL-t egy új dizájnban, amelyen dolgozik, és ezért szerencsés vagyok, hogy tapasztalataim segítenek az Enterprise fórum tervezésében.


Az USB-kapcsolat nyilvánvaló használata a fájlok gyors átvitele lenne az Enterprise és a PC között, az SD-kártyák cseréje nélkül.

Bár az FT245RL másodpercenként 1 millió bájtot képes átvinni, az 1980-as évek más számítógépein szerzett tapasztalatok azt mutatják, hogy nagyobb valószínűséggel kapunk 50-100 ezer bájtot másodpercenként az Enterprise-on.


A tábla elrendezése (3"x 1,75") majdnem kész, ezért azon gondolkodom, hogy hányat rendeljek.

Ha ez működik, és megfizethető (kb. 30 USD vagy 10 000 HUF), érdekelne valakit egy ilyen tábla?


Még egy dolog ... mivel ez GAL-t használ a memória dekódolásához, remélem, hogy boldogan együtt kell élnie a Symbiface3, az EPNET és más meglévő Enterprise bővítő táblákkal.

Jelenleg a C0h-FBh és a B8h-BFh vagy a 78h-7Fh szegmensek használatát tervezem. Láthat valaki ezzel problémát?

Offline Tutus

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Re: Internal memory expansion plus USB
« Reply #1 on: 2021.March.02. 21:47:21 »
If this works, and is affordable (approx $30 USD  or 10,000 HUF), would anyone be interested in a board like this?
This is huge! :smt038 :smt038 :smt038
I'm interested in 2 pieces.
And I see you using the bottom plastic fixing pin. Previous internal memory expansion cards have not used this and are moving. :bow:
Where do you plan to unplug the USB port?
« Last Edit: 2021.March.02. 21:52:56 by Tutus »

Offline elmer

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Re: Internal memory expansion plus USB
« Reply #2 on: 2021.March.02. 22:30:10 »
Where do you plan to unplug the USB port?

A mini-USB connector is mounted on the left hand side of the board.

I am assuming that anyone that really wants to have this USB capability, will be OK with permanently running a standard 2 meter USB cable out of the back of their Enterprise, probably through the existing hole in the Enterprise case used by the Tape Recorder connectors.


And I see you using the bottom plastic fixing pin. Previous internal memory expansion cards have not used this and are moving. :bow:

The board will be large enough that this seemed like a good idea, especially with the weight of the USB cable on the left hand side of the board.

I was lucky that Allf posted his old 64KB board design files last year, and it was possible to measure the exact location of the plastic standoff pin from those. :ds_icon_cheesygrin:

Online geco

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Re: Internal memory expansion plus USB
« Reply #3 on: 2021.March.02. 22:35:44 »
sounds cool I would like also 1 or 1+1 (one for spare)
both planned memory configuration seems to be good.

Offline tofro

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Re: Internal memory expansion plus USB
« Reply #4 on: 2021.March.02. 23:42:48 »
That sounds really good! And I would definitely be interested in a board.

Offline Judge

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Re: Internal memory expansion plus USB
« Reply #5 on: 2021.March.03. 00:26:02 »
I ask for one board, as I wrote in my letter.  :smt024
Üdv.Judge

Offline Dr.OG

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Re: Internal memory expansion plus USB
« Reply #6 on: 2021.March.03. 05:30:46 »
Interested in 1 board.
ÉN ekelek, TE keregsz, Ő gyeleg,
MI ákolunk, TI vornyáztok, ŐK lendeznek.

Offline kokkiklhs

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Re: Internal memory expansion plus USB
« Reply #7 on: 2021.March.03. 09:58:33 »
I'd also like two of these, if possible!
:cool:

Offline BruceTanner

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Re: Internal memory expansion plus USB
« Reply #8 on: 2021.March.03. 10:59:00 »
Just to be clear, in case it is not clear to everyone... this would NOT allow a USB memory stick to be plugged in because it would be a USB slave device. To allow a USB memory stick it would have to be a USB host/master. In the past I have looked for a USB host chip that could be easily interfaced to the EP (ie. a parallel memory mapped type interface) but I could not find one, they all seem to be i2c etc.

But correct me if I am wrong...

Offline tofro

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Re: Internal memory expansion plus USB
« Reply #9 on: 2021.March.03. 13:04:02 »
I hope that was clear for everyone - it was clear to me.

Software for a USB seriel slave is sortof straightforward. USB host, however, is a lot more complicated and probably beyond the scope of an 80'ies Z80 machine, however intelligent the host chip implementation is.

Offline Dr.OG

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Re: Internal memory expansion plus USB
« Reply #10 on: 2021.March.03. 13:15:47 »
Actually I need the memory expansion, as I have an SD card interface and an EXDOS card clone already. USB slave is a bonus. So it's fine to me.
ÉN ekelek, TE keregsz, Ő gyeleg,
MI ákolunk, TI vornyáztok, ŐK lendeznek.

Offline gflorez

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Re: Internal memory expansion plus USB
« Reply #11 on: 2021.March.03. 14:25:41 »
Great idea! I wait expectantly.

Offline elmer

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Re: Internal memory expansion plus USB
« Reply #12 on: 2021.March.03. 18:47:07 »
Just to be clear, in case it is not clear to everyone... this would NOT allow a USB memory stick to be plugged in because it would be a USB slave device. To allow a USB memory stick it would have to be a USB host/master. In the past I have looked for a USB host chip that could be easily interfaced to the EP (ie. a parallel memory mapped type interface) but I could not find one, they all seem to be i2c etc.

But correct me if I am wrong...

You are absolutely correct!

The FT245R's USB connection is just like giving the Enterprise motherboard a fast new serial port that we can connect to a modern PC.

That is all that it does ... but it is something that we don't currently have on the Enterprise, and it can be useful if (and only if) someone writes software on the Enterprise to use it.


For myself, I want to create an Enterprise game on a PC, and then be able to quickly transfer that to a real Enterprise and run it, to make absolutely sure that it works.

This kind of USB connection will allow me to do that (if I write a loader that runs on the Enterprise).


Someone else may want to write some software that allows you to transfer files from the PC to the Enterprise, which would be very useful for downloading new files here on EnterpriseForever, and then copying them to your Enterprise's SD adapter.


Someone might be interested in hacking the EXOS "NET:" driver to use the USB connection (together with a USB hub and a Raspberry Pi), and create a fast network that could play multi-player Enterprise games ... although I suspect that would be unlikely.


Adding the USB hardware to the memory board does nothing by itself, but it is the cheapest and easiest way to enable us to add some extra capability to the Enterprise without getting in the way of the SzörG's wonderful SD Card Adapter, or everyone's hard work on Symbiface3.

Offline dangerman

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Re: Internal memory expansion plus USB
« Reply #13 on: 2021.March.03. 21:38:51 »
Yes, the difficulty with serial is that it's a continuous stream rather than a file system - so we'd have to implement some protocol on top of it to transfer files. I've had a little success using the built in serial port to transfer files from a laptop (slowly), but there's no way of choosing the files from the EP end, and it never knows when the file ends.

However, there's probably already an xmodem client for CP/M or something like that.

Offline Allf

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Re: Internal memory expansion plus USB
« Reply #14 on: 2021.March.04. 06:22:14 »
-  Is it possible to use only the usb expander without memories? (I already have 1 GB built-in + SF3 + FDD interface)
- The amount of shipping cost should be added to the calculated price. (I think.) How much would it be?