Simplest MMC Interface hardware

This is the right place to discuss on how to implement hardware vsync, adding a VIA or AY chipset, puting multiple roms, or how to design a new flash expansion card.
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ibisum
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Re: Simplest MMC Interface hardware

Post by ibisum » Wed Aug 29, 2012 7:52 pm

Goodness, the idea of this hardware project resulting in a Contiki-like environment for an Atmos or two just boggles my mind. Please let me know if there is anything I can do to assist as an early user (Telestrat,Atmos,Oric-1 at the ready!)

;)

The idea of having a full DOS with domain over 512Megs of Oric .DSK's on a single SD just excites me to no end.

I vote for a hardware implementation, however, which requires as little software moderation as possible - if the Microdisc can be emulated to work on a vanilla Oric, would be best of all imho.

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Re: Simplest MMC Interface hardware

Post by jede » Thu Jun 28, 2018 8:49 pm

Dbug wrote:
Sun Aug 19, 2012 8:30 pm
On my side, I have two other questions:
- How expensive/difficult is it to have 8 banks of RAM versus just 2 banks. I guess it's a bigger memory chip with more pins, is that much more problematic to use? If not, why not 16, 32, 64 pages??? (just to push the cork)
six years after, i found this post :)

Twilighte card handles 7*16KB of rom bank like telestrat. But it can also handles 7 banks of RAM and almost 32 banks too because there is a 512KB SRAM on the board. It's not activated in the CPLD, mainly because, it's a bit slow to manage it with software code.

For example, for Orix (telemon initially), keyboard buffer is in RAM overlay. When we read a key, we have to switch to the ram overlay for each keys read.

Well, it's possible on Twilighte card, but as i said it's not activated because i would like to have a mmu instead, if i can handle it on the oric !
Dbug wrote:
Sun Aug 19, 2012 8:30 pm
/me still thinks that having joystick and mouse ports could be awesome, would allow us to make other types of games.
Done also on twilighte card (joysticks and mouse). 3 ways to have mouse on the card :

1) Joystick port : plug a amiga mouse or atari mouse, and driver must be written
2) on joysticks port : with an usb to db9 converter (tom2 for example) and plug a usb mouse : driver must be written too
3) plug the usb mouse in usb port, and the hardware will return delta X & deltaY from the last access to the chip, (coordinates must be read from page 3) Driver must be written too :)

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NekoNoNiaow
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Re: Simplest MMC Interface hardware

Post by NekoNoNiaow » Sat Jul 07, 2018 4:03 pm

Dbug wrote:
Sun Aug 19, 2012 8:30 pm
/me still thinks that having joystick and mouse ports could be awesome, would allow us to make other types of games.
I agree, better/"recent" user input devices go a long way in making a platform easier to use for "modern" activities even if its capabilities are limited.
jede wrote:
Thu Jun 28, 2018 8:49 pm
Done also on twilighte card (joysticks and mouse). 3 ways to have mouse on the card :

1) Joystick port : plug a amiga mouse or atari mouse, and driver must be written
Since the Amiga and Atari mice use quadrature encoded signals to send movement information I assume that this means that there must be code on the Oric which constantly listens to the DB9 inputs and does the quadrature decoding manually? On first thought this looks like this could consume quite a large bit of CPU time.
The Amiga uses dedicated hardware which decodes the quadrature signals and increments corresponding dedicated movement counters (one for each DB9 port) and I assume the Atari ST is the same but that would have to be done entirely in software on the Oric which would be quite expensive.
jede wrote:
Thu Jun 28, 2018 8:49 pm
3) plug the usb mouse in usb port, and the hardware will return delta X & deltaY from the last access to the chip, (coordinates must be read from page 3) Driver must be written too :)
This option looks like it would be much lighter on the Oric since the deltaX/Y would be read directly by the machine and only when needed. In my opinion, unless there is dedicated quadrature decoding hardware on the Twilighte board, this is the most interesting option of the three since it keeps mouse movement querying as simple as possible for the Oric.

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Dbug
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Re: Simplest MMC Interface hardware

Post by Dbug » Sun Jul 08, 2018 8:11 am

NekoNoNiaow wrote:
Sat Jul 07, 2018 4:03 pm
jede wrote:
Thu Jun 28, 2018 8:49 pm
3) plug the usb mouse in usb port, and the hardware will return delta X & deltaY from the last access to the chip, (coordinates must be read from page 3) Driver must be written too :)
This option looks like it would be much lighter on the Oric since the deltaX/Y would be read directly by the machine and only when needed. In my opinion, unless there is dedicated quadrature decoding hardware on the Twilighte board, this is the most interesting option of the three since it keeps mouse movement querying as simple as possible for the Oric.
Not only that, but if done smartly it would also be compatible with some existing software that handled light pens and graphical tablet (graphiscope).
Both of these devices provided with simple registers to read in page 3.

And yes, the Atari ST has a dedicated 8 bit cpu just for the keyboard/joystick/mouse handling, with a custom serial port protocol to transmit information.

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