Timeline for What is the Circuit for a 16K or 32K MSX computer cartridge?
Current License: CC BY-SA 4.0
15 events
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| Nov 25, 2019 at 22:01 | comment | added | Anonymous | You do already have this /OE pin connected to /CS1 or /CS12 which drives chip's output enable. You do not need pull down resistor for passive drive. The phrase you refer to is related to the ROM chip access algorithm, it is not a direct instruction to put some pin in some fixed state - CPU will do it for you using control signals on the bus. | |
| Nov 25, 2019 at 18:36 | comment | added | Rosemary | To directly quote, relevant section, as a copy and paste below (from the page at the link above) " To read the data found at address Ax: Set the address pins to the location that you want to read Ensure that the data bus is not being driven (i.e., floating) Set CS to 0 (to enable the chip) Set OE to 0 " Since the ROM chip in the MSX cartridge is always in a read only state this is why I added the pull down resistor." | |
| Nov 25, 2019 at 18:36 | comment | added | Rosemary | The reason why I put the pull down resistor on OE is as follows. When making a z80 computer OE is set to 0 on a ROM memory for reading (in other words it has a pull down resistor to it) according to "buid your own z80 project part 2 memory" by MakerPro-the link is here maker.pro/pic/projects/… | |
| Nov 25, 2019 at 8:44 | history | edited | Anonymous | CC BY-SA 4.0 | added 1775 characters in body |
| Nov 25, 2019 at 3:20 | comment | added | Rosemary | "The design is very simple" just like you said. | |
| Nov 25, 2019 at 3:19 | comment | added | Rosemary | Regarding my comment Nov 18,13:25; I understand now how the power wiring to cartridge works;so mentioned how the cartridge may be powered using the 4 wires (VPP and GND) | |
| Nov 25, 2019 at 3:19 | comment | added | Rosemary | Added a second circuit. You mention a write pin above; so I made a mention of the write pin in the answer, and I added a resistor for proper chip operation. | |
| Nov 19, 2019 at 7:37 | comment | added | Anonymous | Yes. You also must consult datasheet (e.g. bg-electronics.de/datenblaetter/Schaltkreise/AT27C256.pdf) to ensure you connect other input pins (e.g. WR/Vpp) for proper chip operation. | |
| Nov 18, 2019 at 13:25 | comment | added | Rosemary | Also I am not 100% sure about is what two MSX cartridge pins power the EEPROM from (e.g. maybe you can use pins 43-gnd and 45-VCC to power the EEPROM?). | |
| Nov 18, 2019 at 13:24 | comment | added | Rosemary | Using CS1 means the start of the program code is put into the adresses 4000-7FFF (16K of code space between these addresses) in the EEPROM . Using CS12 means the start of the program code is put into the adresses 8000-7FFF (32K of code space between these addresses) in the EEPROM . Right? | |
| Nov 18, 2019 at 12:44 | comment | added | Rosemary | Also the diagram connects SLTSL to OE, but I think it can be connected to OE or CE ; as you state SLTSL connects to CE. | |
| Nov 14, 2019 at 11:13 | history | edited | Raffzahn | CC BY-SA 4.0 | signal-markup added and contact request removed |
| Nov 14, 2019 at 11:06 | history | edited | Anonymous | CC BY-SA 4.0 | added 94 characters in body |
| Nov 14, 2019 at 10:49 | history | edited | Anonymous | CC BY-SA 4.0 | added 73 characters in body |
| Nov 14, 2019 at 10:42 | history | answered | Anonymous | CC BY-SA 4.0 |