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I opened up my Mark III (Japanese) Space Harrier cartridge in order to discover why it wouldn't work on my SMS via my home-built adapter. This is what I saw:

<strong>Front side</strong>

<img src="http://www.mikeg2.freeserve.co.uk/masterful/mk3spfront.jpg">

<strong>Back side</strong>

<img src="http://www.mikeg2.freeserve.co.uk/masterful/mk3spback.jpg">

This cartridge is unusual in that the game is spread across two 128k ROMs, rather than a single 256k ROM. There are a number of differences as far as the 315-5235 chip connections are concerned:

Pin 15 is connected to _CE of the first (lower 128k) ROM, shown as MPR-10410 in the picture.
Pin 16 is connected to _CE of the second (higher 128k) ROM, labelled MPR-10411.

Pin 24 (normally SRAM _OE) is connected to B3 of the edge connector. I am not sure what pin of the Euro/US SMS this corresponds to (it's not connected in my adaptor), hence I haven't been able to get this cartridge to work on my SMS.

Pins 25 and 26 are connected to +5v.

(Pin 27 is connected to Ground, as usual.)

Pins 13 and 14 (A17 and A18 respectively) are left unconnected.

The above seems to suggest that pins 25 and 26 act as "jumper" pins which change the behaviour of the chip depending on whether they are set high or low.

The 315-5235 was evidently designed to support games spread across two (or more?) ROMs, without requiring additional logic. Perhaps in 1986 (when this cartridge was made), it was cheaper to manufacture two 128k ROMs than a single 256k one?

Mike

mk3spback.jpg (47.5 KB)

Attachment fairy

mk3spfront.jpg (39.75 KB)

Attachment fairy

Quote

> I opened up my Mark III (Japanese) Space Harrier cartridge in order to discover why it wouldn't work on my SMS via my home-built adapter. This is what I saw:

>
> Front side

>

>
> Back side

>

>
> This cartridge is unusual in that the game is spread across two 128k ROMs, rather than a single 256k ROM. There are a number of differences as far as the 315-5235 chip connections are concerned:

> Pin 15 is connected to _CE of the first (lower 128k) ROM, shown as MPR-10410 in the picture.
> Pin 16 is connected to _CE of the second (higher 128k) ROM, labelled MPR-10411.

> Pin 24 (normally SRAM _OE) is connected to B3 of the edge connector. I am not sure what pin of the Euro/US SMS this corresponds to (it's not connected in my adaptor), hence I haven't been able to get this cartridge to work on my SMS.

> Pins 25 and 26 are connected to +5v.

> (Pin 27 is connected to Ground, as usual.)

> Pins 13 and 14 (A17 and A18 respectively) are left unconnected.

> The above seems to suggest that pins 25 and 26 act as "jumper" pins which change the behaviour of the chip depending on whether they are set high or low.

> The 315-5235 was evidently designed to support games spread across two (or more?) ROMs, without requiring additional logic. Perhaps in 1986 (when this cartridge was made), it was cheaper to manufacture two 128k ROMs than a single 256k one?

>
> Mike

Quote

> I opened up my Mark III (Japanese) Space Harrier cartridge in order to discover why it wouldn't work on my SMS via my home-built adapter. This is what I saw:

>
> Front side

>

>
> Back side

>

>
> This cartridge is unusual in that the game is spread across two 128k ROMs, rather than a single 256k ROM. There are a number of differences as far as the 315-5235 chip connections are concerned:

> Pin 15 is connected to _CE of the first (lower 128k) ROM, shown as MPR-10410 in the picture.
> Pin 16 is connected to _CE of the second (higher 128k) ROM, labelled MPR-10411.

> Pin 24 (normally SRAM _OE) is connected to B3 of the edge connector. I am not sure what pin of the Euro/US SMS this corresponds to (it's not connected in my adaptor), hence I haven't been able to get this cartridge to work on my SMS.

> Pins 25 and 26 are connected to +5v.

> (Pin 27 is connected to Ground, as usual.)

> Pins 13 and 14 (A17 and A18 respectively) are left unconnected.

> The above seems to suggest that pins 25 and 26 act as "jumper" pins which change the behaviour of the chip depending on whether they are set high or low.

> The 315-5235 was evidently designed to support games spread across two (or more?) ROMs, without requiring additional logic. Perhaps in 1986 (when this cartridge was made), it was cheaper to manufacture two 128k ROMs than a single 256k one?

>
> Mike

Never mind about Space Harrier. I remembered having opened mine a long time and found out it was unusual.
In fact it is just one of those "big" board with a 315-5235.

Anyway. Today I found out (after a question Mike Gordon asked me) that both The Flash and Desert Speedtrap on the Master System (and probably Game Gear, as I don't have the cartridges) have an onboard RAM chipset.

There is intentionnaly no battery. The RAM is used by both games (made same year by the same developer, so obviously useing the same engine) to store in-game informations about the current level, so there is no need to save such informations.

Also note that there is place and connection for a battery.

desertspeedtrap.jpg (75.51 KB)

Author	Message
Mike G Joined: 21 Apr 2000 Posts: 598 Location: Newcastle upon Tyne, England	Some more 315-5235 info : Space Harrier Mark III Posted: Thu Sep 14, 2000 6:15 pm
	I opened up my Mark III (Japanese) Space Harrier cartridge in order to discover why it wouldn't work on my SMS via my home-built adapter. This is what I saw: <strong>Front side</strong> <img src="http://www.mikeg2.freeserve.co.uk/masterful/mk3spfront.jpg"> <strong>Back side</strong> <img src="http://www.mikeg2.freeserve.co.uk/masterful/mk3spback.jpg"> This cartridge is unusual in that the game is spread across two 128k ROMs, rather than a single 256k ROM. There are a number of differences as far as the 315-5235 chip connections are concerned: Pin 15 is connected to _CE of the first (lower 128k) ROM, shown as MPR-10410 in the picture. Pin 16 is connected to _CE of the second (higher 128k) ROM, labelled MPR-10411. Pin 24 (normally SRAM _OE) is connected to B3 of the edge connector. I am not sure what pin of the Euro/US SMS this corresponds to (it's not connected in my adaptor), hence I haven't been able to get this cartridge to work on my SMS. Pins 25 and 26 are connected to +5v. (Pin 27 is connected to Ground, as usual.) Pins 13 and 14 (A17 and A18 respectively) are left unconnected. The above seems to suggest that pins 25 and 26 act as "jumper" pins which change the behaviour of the chip depending on whether they are set high or low. The 315-5235 was evidently designed to support games spread across two (or more?) ROMs, without requiring additional logic. Perhaps in 1986 (when this cartridge was made), it was cheaper to manufacture two 128k ROMs than a single 256k one? Mike mk3spback.jpg (47.5 KB) Attachment fairy mk3spfront.jpg (39.75 KB) Attachment fairy

Zoop at work Guest	European/US Space Harrier is the same btw nt Posted: Fri Sep 15, 2000 8:24 am
Zoop at work Guest	Quote > I opened up my Mark III (Japanese) Space Harrier cartridge in order to discover why it wouldn't work on my SMS via my home-built adapter. This is what I saw: > > Front side > > > Back side > > > This cartridge is unusual in that the game is spread across two 128k ROMs, rather than a single 256k ROM. There are a number of differences as far as the 315-5235 chip connections are concerned: > Pin 15 is connected to _CE of the first (lower 128k) ROM, shown as MPR-10410 in the picture. > Pin 16 is connected to _CE of the second (higher 128k) ROM, labelled MPR-10411. > Pin 24 (normally SRAM _OE) is connected to B3 of the edge connector. I am not sure what pin of the Euro/US SMS this corresponds to (it's not connected in my adaptor), hence I haven't been able to get this cartridge to work on my SMS. > Pins 25 and 26 are connected to +5v. > (Pin 27 is connected to Ground, as usual.) > Pins 13 and 14 (A17 and A18 respectively) are left unconnected. > The above seems to suggest that pins 25 and 26 act as "jumper" pins which change the behaviour of the chip depending on whether they are set high or low. > The 315-5235 was evidently designed to support games spread across two (or more?) ROMs, without requiring additional logic. Perhaps in 1986 (when this cartridge was made), it was cheaper to manufacture two 128k ROMs than a single 256k one? > > Mike

Zoop at work Guest	European/US Space Harrier is the same btw nt Posted: Fri Sep 15, 2000 8:24 am
Zoop at work Guest	Quote > I opened up my Mark III (Japanese) Space Harrier cartridge in order to discover why it wouldn't work on my SMS via my home-built adapter. This is what I saw: > > Front side > > > Back side > > > This cartridge is unusual in that the game is spread across two 128k ROMs, rather than a single 256k ROM. There are a number of differences as far as the 315-5235 chip connections are concerned: > Pin 15 is connected to _CE of the first (lower 128k) ROM, shown as MPR-10410 in the picture. > Pin 16 is connected to _CE of the second (higher 128k) ROM, labelled MPR-10411. > Pin 24 (normally SRAM _OE) is connected to B3 of the edge connector. I am not sure what pin of the Euro/US SMS this corresponds to (it's not connected in my adaptor), hence I haven't been able to get this cartridge to work on my SMS. > Pins 25 and 26 are connected to +5v. > (Pin 27 is connected to Ground, as usual.) > Pins 13 and 14 (A17 and A18 respectively) are left unconnected. > The above seems to suggest that pins 25 and 26 act as "jumper" pins which change the behaviour of the chip depending on whether they are set high or low. > The 315-5235 was evidently designed to support games spread across two (or more?) ROMs, without requiring additional logic. Perhaps in 1986 (when this cartridge was made), it was cheaper to manufacture two 128k ROMs than a single 256k one? > > Mike

Zoop Joined: 24 Jun 1999 Posts: 1732 Location: Paris, France	Never mind + On Board RAM cartridges Posted: Sat Sep 16, 2000 4:13 pm
	Never mind about Space Harrier. I remembered having opened mine a long time and found out it was unusual. In fact it is just one of those "big" board with a 315-5235. Anyway. Today I found out (after a question Mike Gordon asked me) that both The Flash and Desert Speedtrap on the Master System (and probably Game Gear, as I don't have the cartridges) have an onboard RAM chipset. There is intentionnaly no battery. The RAM is used by both games (made same year by the same developer, so obviously useing the same engine) to store in-game informations about the current level, so there is no need to save such informations. Also note that there is place and connection for a battery. desertspeedtrap.jpg (75.51 KB)

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