Cartridge Device for Oric

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.
highwayman
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Post by highwayman » Wed Nov 16, 2011 2:14 pm

mod the rom so cload/csave sends the filename to a new handler.
the handler will send the name to the external controller via one or more bytes of ram - probably in the 300 area,
then wait for the controller to indicate either "file not found," ready for save" or file found and ready + flags for size, start address, autostart etc.

if your saving, the oric will then pass the file - byte by byte probably to the external system,
if loading, it will read the bytes in and store them acording to the header data.


as for the microcontroller, it would handle the file system, it could translate an attempt to load a file called "list"/"ls" or "dir" by generating a plaintext listing and sending it back as a file.

equally you could have other "codenames"
such as "del-xxx" to delete file xxx

this is true filestorage though, it makes no attempt to emulate an oric disk.
i'm also against storing files as TAP's
what's the point - a TAP is only usefull to store non-standard baudrate/packet-sequence stuff like damsel in distress - if we arent running the included loader in the TAP header then it's pointless.
and we cant run any "fastload" / "bastardized" loader routines such as the ones on some adventure games because they either romcall (the adventure games) or they hit the hardware direct.
so they would both just hang.

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barnsey123
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Post by barnsey123 » Wed Nov 16, 2011 4:02 pm

highwayman wrote:you dont want to be constantly "banging" stuff in,
the ribbon connectors fail after a while if you keep plugging & unplugging them..
The cartridge device would connect to the oric via a ribbon cable but it would contain a slot, into which a cartridge would be placed. There would be no need to keep disconnecting/re-connecting the ribbon cable.
highwayman wrote:infact i think any project these days could be "helped" by interfacing through a microcontroller.
most are more powerfull than the oric & much faster - they could do a lot of the hard work to simplify the software on the oric.
Yes, there's an atari device (SIO2PC) that allows an 8-bit atari to connect to a PC via USB or RS232- the device contains a 48mhz MPU, some flash memory and other bits. On the PC side some software talks to it and serves up PC files as atari disks. The atari thinks it's attached to a normal disk drive and the SIO2PC does all the hard work. A similar concept could be applied to the oric, with the oric "seeing" PC files as microdisks. This would also allow the oric to access other resources on the PC (e.g. printers).

I have one on order for my 800XL and will let you know how it works in practice.

CLODE ALONE

As for TAPs - I'd LIKE to see a cart with collections of games accessed by a menu. Most of these games will of course be TAP files (originally) but this doesn't matter. Different carts could behave in different ways - one cart might be geared up for tapedrive emulation, another for disk, it's up to whoever is flashing the cart. The ROM on the "disk" cartridge would leave "CLOAD" alone, but the "tape" cartridge ROM would re-direct it (in the manner describe above by Dbug).

It's the cart that overlays the ROM and hence the behaviour of the oric...

If this device also has a pass-thru port then things like the Cumulus and original microdisc could work in tandem (as long as there is nothing in the cart slot then all would be well...I think...)

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Post by Dbug » Wed Nov 16, 2011 5:36 pm

highwayman wrote:i'm also against storing files as TAP's
what's the point - a TAP is only usefull to store non-standard baudrate/packet-sequence stuff like damsel in distress - if we arent running the included loader in the TAP header then it's pointless.
and we cant run any "fastload" / "bastardized" loader routines such as the ones on some adventure games because they either romcall (the adventure games) or they hit the hardware direct.
so they would both just hang.
I don't see what the problem with TAP files, they are not anything weird, they are just normal binary files with a header that tells the name, location and type of the file, there's no encoding, it's just pure byte stream that you can copy directly into memory and run. The header itself is like 13 bytes long, so it does not take memory either.

And pretty much all software uses normal routines, I can thing of a grand maximum of 10 software that used custom loading routines.

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Post by Symoon » Wed Nov 16, 2011 10:46 pm

Dbug wrote:And pretty much all software uses normal routines, I can thing of a grand maximum of 10 software that used custom loading routines.
On the (more or less) 500 tapes I've seen or transfered, I count around 50 specific routines. So about 10%

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Post by Godzil » Thu Nov 17, 2011 12:04 am

Wow some even make "protection copy" on tapes ? ;)


Anyway, making "cardridge" the way is discribe actully is for me a non sens. It will be more easier and powerful to do a bus like the AppleII or the ISA bus, both are possible to make on the Oric, and both will provide a lots of ready to use card. Look at the AppleII scene, they have IDE cards, SCSI cards, Ethenet card, and they use the SAME CPU (and the AII schematic is really simple). Even the floppy controller is simpler than the microdisk/jasmin one ;)

anyway. I have a lots of hardware idea for the Oric, and I will share with you when they become more than simple ideas ;) (but slot based extention mechanism is one of them btw)

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Post by highwayman » Thu Nov 17, 2011 1:24 pm

on the cbm/atari machines the cartridge port is very close to the cpu,

if you want a backplane like apple, or tangerine etc, you need to buffer the bus and be very careful about track routing.

but more importantly, you would want to open the oric & rip that damned 7905 regulator out.
replace it with a jumper and feed both the oric & backplane from a decent switching psu.
one that regulates the positive rail(s) and not the damned groundplane!!! :evil:

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Post by highwayman » Thu Nov 17, 2011 1:30 pm

infact thinking about that,

these days you can get small wall-bricks - less than half the size of the oric's 600ma(ish) psu that contain a switching psu with a 5v 1.5a output.
i'v seen them at junk sales for a € or 2 from routers & stuff.

i'm gonna get a few - once i find my real orics i'm gonna rip the regulators out & feed them with these modern 5v supply's
8)

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Post by barnsey123 » Sat Nov 19, 2011 5:01 pm

highwayman wrote:...but more importantly, you would want to open the oric & rip that damned 7905 regulator out.
replace it with a jumper and feed both the oric & backplane from a decent switching psu.
one that regulates the positive rail(s) and not the damned groundplane!!!
Do you think that the 7905 is the cause of all the problems with the oric bus, or is it more complicated than that?

Barnsey

highwayman
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Post by highwayman » Sat Nov 19, 2011 8:41 pm

if your using something on the bus that has it's own psu - even if it's just an inline regulator or zener diode then it can be a problem.

infact it was stupid of tangerine's engineers and they should have known better - all it did was save a few pence - literally on the mfr costs.

infact it bit them in the ass pretty fast - they had to create a BIG psu for the microdrives that also powered the oric to avoid the 2 supply problem!

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Re:

Post by kenneth » Fri Dec 20, 2013 10:14 pm

Dbug wrote:Ok, let's assume we have no cost problems, and that we want this thing to be as compatible as possible, it would mean that basically it has to load tapes, if possible non modified.

A possibility would be to have a device that embeds a copy of the Atmos ROM, with the only changes being the tape loading code (at the same addresses so code that calls directly the 'get header', etc... would work).

So the device would play with the ROM and overlays like the standard Microdisc unit does, showing the copied ROM instead of the real ROM, and I guess some page 3 address can be used to select one of multiple pages of memory (possibly mapped from a flash unit) and then copied to normal rom with standard system variables in page 2 updated to reflect a real tape load, and when done give back control to the calling code as if it was back from an actual CLOAD"" ?
It could be like this
A 64k ROM cartridge with a copy of OricBasic modified with a routine used to copy the loader into page #400 that will copy the content of the rest of the EPROM from a switchable bank with a I/O address
I made this hypothetic schema
Image

and a pcb diagram

Image

But I must try it before :D
Last edited by kenneth on Sun Mar 09, 2014 5:19 pm, edited 2 times in total.

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barnsey123
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Re: Cartridge Device for Oric

Post by barnsey123 » Sat Dec 21, 2013 4:31 pm

@kenneth...looks cool...don't understand it but it looks cool :)

Can you build it?

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Re: Cartridge Device for Oric

Post by kenneth » Sat Dec 21, 2013 8:56 pm

I'll try to build it. I bought the test card and the components. I need to burn a 64K EPROM with four versions of ROM ORIC and try to "switch" them while writing into adr #3F3. If the result is good I will replace the contents of the EPROM by a 48Ko game.
I hope that the ORIC's regulator will work a little more for my interface.
Using ORIC with cartridges is an old dream. It could be an other interesting solution to play with the real machine like Cumulus.

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kenneth
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Re: Cartridge Device for Oric

Post by kenneth » Wed Feb 26, 2014 8:33 pm

Good news :D
I modified the PCB by inverting of the clk signal on the d toggle,
I tested with Xenon1: success!
the autostart did not work: I must type RUN after Oric device switched on
Someone knows the address of the "RUN" routine ?

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peacer
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Re: Cartridge Device for Oric

Post by peacer » Thu Feb 27, 2014 1:31 am

RUN Command routines
1.0 ROM : CALL #C733
1.1 ROM : CALL #C708

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barnsey123
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Re: Cartridge Device for Oric

Post by barnsey123 » Thu Feb 27, 2014 10:08 am

kenneth wrote:Good news :D
I modified the PCB by inverting of the clk signal on the d toggle,
I tested with Xenon1: success!
the autostart did not work: I must type RUN after Oric device switched on
Someone knows the address of the "RUN" routine ?
Any pictures?

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