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I made a SMS mapper circuit that can control up to 512kbytes (4mbits) ROM. It works exactly like these
one-chip catridges. I only implemented the frame 2, but it works perfectly. The only game I tried and doesn't ran
was Sonic1, which uses page 1 for pagination.

The following games were tested :
Shooting Gallery
Alex Kidd in Miracle World
Alex Kidd BMX Trial
Space Harrier 3D
Kenseiden (japanese version)
R-Type (original mask ROM chip, same pinout as 27C040/27C4001)
Phantasy Star (both NTSC versions)
SDI
Sonic The Hedgehog (the only that doesn't worked.

I'm going to post schematics here this sunday ... I still need to "clean" the schematics
I think the schematics will be usefull for anyone who have guts to assembly a device that has
10 TTL chips, or use PLD/FPGA chips...

Cya ...

Quote

> I'm going to post schematics here this sunday ... I still need to "clean" the schematics
> I think the schematics will be usefull for anyone who have guts to assembly a device that has
> 10 TTL chips, or use PLD/FPGA chips...

I'd love to get my hands on a device that can program PLD's (and, while I'm at it, get my hands on some blank PLD's), since the whole mess could easily be condensed into a single chip. Definately a good option if one were intersted in produce a volume of carts (maybe publishing a best-of s8-dev cart and selling in limited numbers... not that there's much to fill up a cartridge with but...)

someone here (forget who) claimed they had a mapper that mapped all three frame (pages, banks, blah blah. the 16k regions) with three (or four?) common TTL's.

Quote

> > I'm going to post schematics here this sunday ... I still need to "clean" the schematics
> > I think the schematics will be usefull for anyone who have guts to assembly a device that has
> > 10 TTL chips, or use PLD/FPGA chips...

> I'd love to get my hands on a device that can program PLD's (and, while I'm at it, get my hands on some blank PLD's),
> since the whole mess could easily be condensed into a single chip.
> Definately a good option if one were intersted in produce a volume of carts (maybe publishing a best-of s8-dev cart and
> selling in limited numbers... not that there's much to fill up a cartridge with but...)

> someone here (forget who) claimed they had a mapper that mapped all three frame (pages, banks, blah blah.
> the 16k regions) with three (or four?) common TTL's.

Well ... If I forget about the flip-flops I used and change it to the 74LS670 ( 4 bit addressable registers), I'm sure
I can drop 2 chips on the design. I can also expand the design to address up to 4096 kbytes in a wonderfull
total of 32 megabits of address space. The only Z80 based machines I saw with a such mapped address space
was a MSX computer with expanded memory cartridge. I think that for now it's more important to simplify the circuit
and inplement the SRAM register. Latter, with a simplified addressing logic, I'll implement a 2 bank mapper.
Mapping the bank 0 is really useless and also adds 2 chips and a lot of wires to the design, just a waste of silicon ...
Just to mention, I used a standard prototype board and "wire-up" to join the parts together. Then think how much time
it took from me to figure out the workings of the mapper and worse, the effort to assembly it ... I just put a lot of
my sweat in it ...

Think about ... =)

10 chips! do they fit in a standard cart case?!?

my design uses only 4 (if i remember correctly...) simple and cheap 74LS chips. it can also support 256 pages in any of the frames/etc..

mind you, it IS only a design at this stage and i haven't tested it, so if you have a working design then i take my hat off to you sir.

a s out.

Quote

> 10 chips! do they fit in a standard cart case?!?
> my design uses only 4 (if i remember correctly...) simple and cheap 74LS chips. it can also support 256 pages in any of the frames/etc..
> mind you, it IS only a design at this stage and i haven't tested it, so if you have a working design then i take my hat off to you sir.
> a s out.

It has 10 chips because I used 4 chips 74ls74 (dual flip-flop type D) chips to build the register. I used them, because they
allow you to program their initial status after a reset cycle. Then I emulated the behaviour of a 28 pin rom/mapper chip.
These chips aways show it's page 3 in the frame 2 after the porver-on. I don't think that it's required, but I wanted to implement
it on the design. I'll change them for a addressable register (74ls670) latter...

I'm really interested in your design ... May you send it to me ? (after I post my design in the forum, to proof that it has only my stuff on it ...)
=)

(I guess I got a exelent usage of my spare time this week !!! 2 important hacks in the SMS hardware and this mapper design)

I connected the mapper board to the SMS thuru the expansion port (My SMS is a old first model TecToy Power base).
As most of you guys know, it has 3 slots available for connection. I used the expansion port because it's easy to get a female
50 pin connector with flat cable connector (SCSI cable) and then put it in a prototype board.

Also, I don't need to unplug it from the SMS or even remove the EPROM from it to use a cartridge. Since the cartridge slot has
higher priority than the expansion port, by plugging a cartridge the game in it will boot normally and the mapper board will stay
inactive.

I hope you liked this idea ... The only drawback on the way I assembled my mapper is that you can't use it with the SMS2 or
Mega Drive with power base adaptor. But, if desired, the design can be used to make a cartridge...

Quote

> I connected the mapper board to the SMS thuru the expansion port (My SMS is a old first model TecToy Power base).
> As most of you guys know, it has 3 slots available for connection. I used the expansion port because it's easy to get a female
> 50 pin connector with flat cable connector (SCSI cable) and then put it in a prototype board.

Actually, I never heard of a third slot: this is a bus-mapped (like the card slot) adaptor with a plug that's equivelant to a 50 pin scsi connector?

Quote

> > I connected the mapper board to the SMS thuru the expansion port (My SMS is a old first model TecToy Power base).
> > As most of you guys know, it has 3 slots available for connection. I used the expansion port because it's easy to get a female
> > 50 pin connector with flat cable connector (SCSI cable) and then put it in a prototype board.

> Actually, I never heard of a third slot: this is a bus-mapped (like the card slot) adaptor with a plug that's equivelant to a 50 pin scsi connector?

I don't know if the US/Europe versions of the SMS had the same connector. Actually it just look like the Mega Drive expansion port. But has the same pinout
as the cartridge slot. If you look at the schematics from Gringoz, that schematic do refer to 3 slot connectors. the small one in the left is the card slot, the middle one
is the cartridge slot and the third one is where I'm connecting my prototype board. Also, look at the topic "Mark 3/ Japanese SMS FM hardware". There's have a picture
of my SMS open at that post. In the picture you can see the connector I'm using behind the cartridge slot.

Quote

> I don't know if the US/Europe versions of the SMS had the same connector. Actually it just look like the Mega Drive expansion port. But has the same pinout
> as the cartridge slot. If you look at the schematics from Gringoz, that schematic do refer to 3 slot connectors. the small one in the left is the card slot, the middle one
> is the cartridge slot and the third one is where I'm connecting my prototype board. Also, look at the topic "Mark 3/ Japanese SMS FM hardware". There's have a picture
> of my SMS open at that post. In the picture you can see the connector I'm using behind the cartridge slot.

Well, be damned, there is an expansion port in the very back of the sms. There's a pullout slot that looks like you'd open it up to put batteries in, and the expansion port inside (a cartridge-looking edge connector) is protected by plastic mounting that you'd have to physically break out to be able to get past it. How strange.

Apparently early nes's also had an expansion port that was completely hidden inside the box itself, as if they decided at the last minute to take it out of the design.

Author	Message
Vic_Viper Joined: 12 Jul 2005 Posts: 55	Homemade SMS cartridge. Posted: Fri Sep 01, 2000 11:29 pm
Vic_Viper Joined: 12 Jul 2005 Posts: 55	I made a SMS mapper circuit that can control up to 512kbytes (4mbits) ROM. It works exactly like these one-chip catridges. I only implemented the frame 2, but it works perfectly. The only game I tried and doesn't ran was Sonic1, which uses page 1 for pagination. The following games were tested : Shooting Gallery Alex Kidd in Miracle World Alex Kidd BMX Trial Space Harrier 3D Kenseiden (japanese version) R-Type (original mask ROM chip, same pinout as 27C040/27C4001) Phantasy Star (both NTSC versions) SDI Sonic The Hedgehog (the only that doesn't worked. I'm going to post schematics here this sunday ... I still need to "clean" the schematics I think the schematics will be usefull for anyone who have guts to assembly a device that has 10 TTL chips, or use PLD/FPGA chips... Cya ...

Heliophobe Site Admin Joined: 25 Oct 1999 Posts: 2029 Location: Monterey, California	superstar Posted: Sat Sep 02, 2000 1:01 am
	Quote > I'm going to post schematics here this sunday ... I still need to "clean" the schematics > I think the schematics will be usefull for anyone who have guts to assembly a device that has > 10 TTL chips, or use PLD/FPGA chips... I'd love to get my hands on a device that can program PLD's (and, while I'm at it, get my hands on some blank PLD's), since the whole mess could easily be condensed into a single chip. Definately a good option if one were intersted in produce a volume of carts (maybe publishing a best-of s8-dev cart and selling in limited numbers... not that there's much to fill up a cartridge with but...) someone here (forget who) claimed they had a mapper that mapped all three frame (pages, banks, blah blah. the 16k regions) with three (or four?) common TTL's.

Vic_Viper Joined: 12 Jul 2005 Posts: 55	Re: superstar Posted: Sat Sep 02, 2000 2:19 am
Vic_Viper Joined: 12 Jul 2005 Posts: 55	Quote > > I'm going to post schematics here this sunday ... I still need to "clean" the schematics > > I think the schematics will be usefull for anyone who have guts to assembly a device that has > > 10 TTL chips, or use PLD/FPGA chips... > I'd love to get my hands on a device that can program PLD's (and, while I'm at it, get my hands on some blank PLD's), > since the whole mess could easily be condensed into a single chip. > Definately a good option if one were intersted in produce a volume of carts (maybe publishing a best-of s8-dev cart and > selling in limited numbers... not that there's much to fill up a cartridge with but...) > someone here (forget who) claimed they had a mapper that mapped all three frame (pages, banks, blah blah. > the 16k regions) with three (or four?) common TTL's. Well ... If I forget about the flip-flops I used and change it to the 74LS670 ( 4 bit addressable registers), I'm sure I can drop 2 chips on the design. I can also expand the design to address up to 4096 kbytes in a wonderfull total of 32 megabits of address space. The only Z80 based machines I saw with a such mapped address space was a MSX computer with expanded memory cartridge. I think that for now it's more important to simplify the circuit and inplement the SRAM register. Latter, with a simplified addressing logic, I'll implement a 2 bank mapper. Mapping the bank 0 is really useless and also adds 2 chips and a lot of wires to the design, just a waste of silicon ... Just to mention, I used a standard prototype board and "wire-up" to join the parts together. Then think how much time it took from me to figure out the workings of the mapper and worse, the effort to assembly it ... I just put a lot of my sweat in it ... Think about ... =)

asynchronous Joined: 14 Aug 2000 Posts: 742 Location: Adelaide, Australia	Re: full mapper with just 4 chips Posted: Sat Sep 02, 2000 6:29 am
	10 chips! do they fit in a standard cart case?!? my design uses only 4 (if i remember correctly...) simple and cheap 74LS chips. it can also support 256 pages in any of the frames/etc.. mind you, it IS only a design at this stage and i haven't tested it, so if you have a working design then i take my hat off to you sir. a s out.

Vic_Viper Joined: 12 Jul 2005 Posts: 55	Re: full mapper with just 4 chips Posted: Sat Sep 02, 2000 3:42 pm
Vic_Viper Joined: 12 Jul 2005 Posts: 55	Quote > 10 chips! do they fit in a standard cart case?!? > my design uses only 4 (if i remember correctly...) simple and cheap 74LS chips. it can also support 256 pages in any of the frames/etc.. > mind you, it IS only a design at this stage and i haven't tested it, so if you have a working design then i take my hat off to you sir. > a s out. It has 10 chips because I used 4 chips 74ls74 (dual flip-flop type D) chips to build the register. I used them, because they allow you to program their initial status after a reset cycle. Then I emulated the behaviour of a 28 pin rom/mapper chip. These chips aways show it's page 3 in the frame 2 after the porver-on. I don't think that it's required, but I wanted to implement it on the design. I'll change them for a addressable register (74ls670) latter... I'm really interested in your design ... May you send it to me ? (after I post my design in the forum, to proof that it has only my stuff on it ...) =) (I guess I got a exelent usage of my spare time this week !!! 2 important hacks in the SMS hardware and this mapper design)

Vic_Viper Joined: 12 Jul 2005 Posts: 55	Oops, I forgot to mention how I connected the mapper stuff on the SMS ... ;) Posted: Sat Sep 02, 2000 4:05 pm
Vic_Viper Joined: 12 Jul 2005 Posts: 55	I connected the mapper board to the SMS thuru the expansion port (My SMS is a old first model TecToy Power base). As most of you guys know, it has 3 slots available for connection. I used the expansion port because it's easy to get a female 50 pin connector with flat cable connector (SCSI cable) and then put it in a prototype board. Also, I don't need to unplug it from the SMS or even remove the EPROM from it to use a cartridge. Since the cartridge slot has higher priority than the expansion port, by plugging a cartridge the game in it will boot normally and the mapper board will stay inactive. I hope you liked this idea ... The only drawback on the way I assembled my mapper is that you can't use it with the SMS2 or Mega Drive with power base adaptor. But, if desired, the design can be used to make a cartridge...

Heliophobe Site Admin Joined: 25 Oct 1999 Posts: 2029 Location: Monterey, California	expansion whatsit? Posted: Sat Sep 02, 2000 11:10 pm
	Quote > I connected the mapper board to the SMS thuru the expansion port (My SMS is a old first model TecToy Power base). > As most of you guys know, it has 3 slots available for connection. I used the expansion port because it's easy to get a female > 50 pin connector with flat cable connector (SCSI cable) and then put it in a prototype board. Actually, I never heard of a third slot: this is a bus-mapped (like the card slot) adaptor with a plug that's equivelant to a 50 pin scsi connector?

Vic_Viper Joined: 12 Jul 2005 Posts: 55	Re: expansion whatsit? Posted: Sun Sep 03, 2000 2:26 am
Vic_Viper Joined: 12 Jul 2005 Posts: 55	Quote > > I connected the mapper board to the SMS thuru the expansion port (My SMS is a old first model TecToy Power base). > > As most of you guys know, it has 3 slots available for connection. I used the expansion port because it's easy to get a female > > 50 pin connector with flat cable connector (SCSI cable) and then put it in a prototype board. > Actually, I never heard of a third slot: this is a bus-mapped (like the card slot) adaptor with a plug that's equivelant to a 50 pin scsi connector? I don't know if the US/Europe versions of the SMS had the same connector. Actually it just look like the Mega Drive expansion port. But has the same pinout as the cartridge slot. If you look at the schematics from Gringoz, that schematic do refer to 3 slot connectors. the small one in the left is the card slot, the middle one is the cartridge slot and the third one is where I'm connecting my prototype board. Also, look at the topic "Mark 3/ Japanese SMS FM hardware". There's have a picture of my SMS open at that post. In the picture you can see the connector I'm using behind the cartridge slot.

Heliophobe Site Admin Joined: 25 Oct 1999 Posts: 2029 Location: Monterey, California	the things you learn... Posted: Sun Sep 03, 2000 5:46 am
	Quote > I don't know if the US/Europe versions of the SMS had the same connector. Actually it just look like the Mega Drive expansion port. But has the same pinout > as the cartridge slot. If you look at the schematics from Gringoz, that schematic do refer to 3 slot connectors. the small one in the left is the card slot, the middle one > is the cartridge slot and the third one is where I'm connecting my prototype board. Also, look at the topic "Mark 3/ Japanese SMS FM hardware". There's have a picture > of my SMS open at that post. In the picture you can see the connector I'm using behind the cartridge slot. Well, be damned, there is an expansion port in the very back of the sms. There's a pullout slot that looks like you'd open it up to put batteries in, and the expansion port inside (a cartridge-looking edge connector) is protected by plastic mounting that you'd have to physically break out to be able to get past it. How strange. Apparently early nes's also had an expansion port that was completely hidden inside the box itself, as if they decided at the last minute to take it out of the design.

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