FlexROM 100 - Revision history

Bkw: /* What Is This? */

2025-10-23T18:17:54Z

What Is This?

← Older revision		Revision as of 18:17, 23 October 2025
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	There are a few reasons why it might be nice to be able to edit or replace the system rom on any computer, including a Model 100.<br>		There are a few reasons why it might be nice to be able to edit or replace the system rom on any computer, including a Model 100.<br>
	In the case of the Model 100, the simplest reason is just the [[Model_T_Y2K\|Y2K Patch]].<br>		In the case of the Model 100, the simplest reason is just the [[Model_T_Y2K\|Y2K Patch]].<br>
	But there are other possible things like fixing bugs or even customizing the rom software.		But there are other possible things like fixing bugs or even customizing the rom software.<br>
			One awesome example is [https://sarahkmarr.com/retromodel100.html LibROM].

	This board allows replacing the system rom in two different ways, directly, and via REX.		This board allows replacing the system rom in two different ways, directly, and via REX.

Bkw: /* EEPROM Version */

2024-01-04T22:28:28Z

EEPROM Version

← Older revision		Revision as of 22:28, 4 January 2024
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	===EEPROM Version===		===EEPROM Version===
	~~FlexROM_100 PCB:~~ https://~~oshpark~~.com/~~shared_projects~~/~~r2z7rsUs<br>~~		[https://github.com/bkw777/aDIPters#flexrom_100 FlexROM_100 PCB & BOM]<br>
	FlexROM_100 ~~BOM: https://www.digikey.com/short/z003bc<br>~~		[https://github.com/bkw777/aDIPters#flexrom_100-programming-adapter FlexROM_100 programming adapter]

	~~Programming Adapter~~ PCB~~: https://oshpark.com/shared_projects/9p1qXiV2<br>~~
	~~Programming Adapter~~ BOM~~: https://www.digikey.com/short/zdb91j~~<br>

	~~KiCAD schematic and pcb sources:~~ https://github.com/bkw777/aDIPters

	Some more assembly and usage details: https://photos.app.goo.gl/BkHg3CCciFGxzECW6		Some more assembly and usage details: https://photos.app.goo.gl/BkHg3CCciFGxzECW6

	~~(Latest~~ version doesn't exactly match the pictures above, because now there is a programming adapter, and you don't need an SOIC-28 test clip any more.)		The current version doesn't exactly match the pictures above, because now there is a programming adapter, and you don't need an SOIC-28 test clip and ribbon cables any more.

	===FLASH version===		===FLASH version===

Bkw: /* FLASH version */

2024-01-04T22:25:34Z

FLASH version

← Older revision		Revision as of 22:25, 4 January 2024
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	===FLASH version===		===FLASH version===
	~~Reason:~~ 28C256 is over $9. SST39SF010A is ~~only~~ $~~1.<br>~~		28C256 is over $10. SST39SF010A is under $2.
	~~The chip is 128K, but only 32K is used~~.

	~~PCB:~~ https://~~oshpark~~.com/~~shared_projects~~/~~6bESPETR~~<br>		[https://github.com/bkw777/aDIPters#flashrom_100 FlashROM_100]<br>
	~~Programming Adapter:~~ https://~~oshpark~~.com/~~shared_projects~~/~~JAV4uaZH~~<br>		[https://github.com/bkw777/aDIPters#tsop FlashROM_100 PCB & BOM]<br>
	~~Flash chip:~~ https://~~www.digikey~~.com/~~short~~/~~zd24d7~~		[https://github.com/bkw777/aDIPters#flashrom_100-programming-adapter FlashROM_100 programming adapter]

	== What Is This? ==		== What Is This? ==

Bkw: /* What Is This? */

2023-10-12T18:12:53Z

What Is This?

← Older revision		Revision as of 18:12, 12 October 2023
Line 56:		Line 56:
	Additionally, it provides a connection point for a [[REX]] to use REX's [http://bitchin100.com/wiki/index.php?title=Main_ROM_Management_Feature Main ROM Management Feature] without having to remove the internal rom.		Additionally, it provides a connection point for a [[REX]] to use REX's [http://bitchin100.com/wiki/index.php?title=Main_ROM_Management_Feature Main ROM Management Feature] without having to remove the internal rom.

	There are a few reasons why it might be nice to be able to edit or replace the system rom on any computer, including a Model 100.		There are a few reasons why it might be nice to be able to edit or replace the system rom on any computer, including a Model 100.<br>
	In the case of the Model 100, the simplest reason is just the [~~http://www.muppetlabs.com/~chris/model100/m100y2k.pdf~~ Y2K ~~patch~~]		In the case of the Model 100, the simplest reason is just the [[Model_T_Y2K\|Y2K Patch]].<br>
	But there are other possible things like fixing bugs or even customizing the rom software.		But there are other possible things like fixing bugs or even customizing the rom software.

Bkw: /* EEPROM adapter for TRS-80 Model 100 system ROM */

2021-03-04T08:58:24Z

EEPROM adapter for TRS-80 Model 100 system ROM

← Older revision		Revision as of 08:58, 4 March 2021
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	The new version uses a flash part: 29F010 (SST39SF010A)<br>		The new version uses a flash part: 29F010 (SST39SF010A)<br>

	EEPROM Version~~:<br>~~		===EEPROM Version===
	FlexROM_100 PCB: https://oshpark.com/shared_projects/r2z7rsUs<br>		FlexROM_100 PCB: https://oshpark.com/shared_projects/r2z7rsUs<br>
	FlexROM_100 BOM: https://www.digikey.com/short/z003bc<br>		FlexROM_100 BOM: https://www.digikey.com/short/z003bc<br>
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	(Latest version doesn't exactly match the pictures above, because now there is a programming adapter, and you don't need an SOIC-28 test clip any more.)		(Latest version doesn't exactly match the pictures above, because now there is a programming adapter, and you don't need an SOIC-28 test clip any more.)

	FLASH version~~:<br>~~		===FLASH version===
	Reason: 28C256 is over $9. SST39SF010A is only $1.<br>		Reason: 28C256 is over $9. SST39SF010A is only $1.<br>
	The chip is 128K, but only 32K is used.		The chip is 128K, but only 32K is used.
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	== What Is This? ==		== What Is This? ==

	This is an adapter board that allows plugging a standard eeprom into the Model 100's non-standad pinout system rom socket.		This is an adapter board that allows plugging a standard eeprom into the Model 100's non-standad pinout system rom socket.

Bkw: /* EEPROM adapter for TRS-80 Model 100 system ROM */

2021-03-04T08:57:14Z

EEPROM adapter for TRS-80 Model 100 system ROM

← Older revision		Revision as of 08:57, 4 March 2021
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	</gallery>		</gallery>

	~~FlexROM_100 PCB~~: ~~https~~:~~//oshpark.com/shared_projects/r2z7rsUs~~		There are 2 versions of this. The original version uses an EEPROM part: 28C256<br>
			The new version uses a flash part: 29F010 (SST39SF010A)<br>

	FlexROM_100 BOM: https://www.digikey.com/short/z003bc		EEPROM Version:<br>
			FlexROM_100 PCB: https://oshpark.com/shared_projects/r2z7rsUs<br>
			FlexROM_100 BOM: https://www.digikey.com/short/z003bc<br>

	Programming Adapter PCB: https://oshpark.com/shared_projects/9p1qXiV2		Programming Adapter PCB: https://oshpark.com/shared_projects/9p1qXiV2<br>
			Programming Adapter BOM: https://www.digikey.com/short/zdb91j<br>
	Programming Adapter BOM: https://www.digikey.com/short/zdb91j

	KiCAD schematic and pcb sources: https://github.com/bkw777/aDIPters		KiCAD schematic and pcb sources: https://github.com/bkw777/aDIPters
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	Some more assembly and usage details: https://photos.app.goo.gl/BkHg3CCciFGxzECW6		Some more assembly and usage details: https://photos.app.goo.gl/BkHg3CCciFGxzECW6

	(Latest version doesn't exactly match the pictures above, because now there is a programming adapter ~~instead of needing the~~ SOIC-28 test clip~~, and there is a 2nd set of jumper pins on the board for write-enable~~.)		(Latest version doesn't exactly match the pictures above, because now there is a programming adapter, and you don't need an SOIC-28 test clip any more.)

	~~----~~		FLASH version:<br>
	~~2020-11-23 - UN-TESTED new alternative~~ version~~<br>~~		Reason: 28C256 is over $9. SST39SF010A is only $1.<br>
	~~Using a 29F010-compatible flash chip instead of a 28C256 EEPROM~~<br>
	Reason: 28C256 is over $9. ~~SST39SF010~~ is only $1.<br>
	The chip is 128K, but only 32K is used.		The chip is 128K, but only 32K is used.

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	Programming Adapter: https://oshpark.com/shared_projects/JAV4uaZH<br>		Programming Adapter: https://oshpark.com/shared_projects/JAV4uaZH<br>
	Flash chip: https://www.digikey.com/short/zd24d7		Flash chip: https://www.digikey.com/short/zd24d7
	~~----~~

	== What Is This? ==		== What Is This? ==

Bkw at 10:50, 23 November 2020

2020-11-23T10:50:42Z

← Older revision		Revision as of 10:50, 23 November 2020
Line 41:		Line 41:
	(Latest version doesn't exactly match the pictures above, because now there is a programming adapter instead of needing the SOIC-28 test clip, and there is a 2nd set of jumper pins on the board for write-enable.)		(Latest version doesn't exactly match the pictures above, because now there is a programming adapter instead of needing the SOIC-28 test clip, and there is a 2nd set of jumper pins on the board for write-enable.)

	~~<!--~~
	----		----
	2020-11-23 - UN-TESTED new alternative version<br>		2020-11-23 - UN-TESTED new alternative version<br>
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	Flash chip: https://www.digikey.com/short/zd24d7		Flash chip: https://www.digikey.com/short/zd24d7
	----		----
	~~-->~~

	== What Is This? ==		== What Is This? ==

Bkw: /* EEPROM adapter for TRS-80 Model 100 system ROM */

2020-11-23T10:50:24Z

EEPROM adapter for TRS-80 Model 100 system ROM

← Older revision		Revision as of 10:50, 23 November 2020
Line 43:		Line 43:
	<!--		<!--
	----		----
	2020-11-05<br>		2020-11-23 - UN-TESTED new alternative version<br>
	~~New alternative version using~~ a 29F010-compatible flash chip instead of a 28C256 EEPROM~~<br>~~		Using a 29F010-compatible flash chip instead of a 28C256 EEPROM<br>
	~~This is untested yet.~~<br>
	Reason: 28C256 is over $9. SST39SF010 is only $1.<br>		Reason: 28C256 is over $9. SST39SF010 is only $1.<br>
	The chip is 128K, but only 32K is used.		The chip is 128K, but only 32K is used.

	PCB: https://oshpark.com/shared_projects/~~V3JxeXcf~~<br>		PCB: https://oshpark.com/shared_projects/6bESPETR<br>
	Programming Adapter: https://oshpark.com/shared_projects/JAV4uaZH<br>		Programming Adapter: https://oshpark.com/shared_projects/JAV4uaZH<br>
	Flash chip: https://www.digikey.com/short/zd24d7		Flash chip: https://www.digikey.com/short/zd24d7

Bkw: /* EEPROM adapter for TRS-80 Model 100 system ROM */

2020-11-23T10:04:34Z

EEPROM adapter for TRS-80 Model 100 system ROM

← Older revision		Revision as of 10:04, 23 November 2020
Line 38:		Line 38:

	Some more assembly and usage details: https://photos.app.goo.gl/BkHg3CCciFGxzECW6		Some more assembly and usage details: https://photos.app.goo.gl/BkHg3CCciFGxzECW6

			(Latest version doesn't exactly match the pictures above, because now there is a programming adapter instead of needing the SOIC-28 test clip, and there is a 2nd set of jumper pins on the board for write-enable.)

	<!--		<!--

Bkw: /* Building */

2020-11-23T10:01:29Z

Building

← Older revision		Revision as of 10:01, 23 November 2020
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	The only notes to add are what's the best order to proceed and why, and the best way to do the dip-28 legs.		The only notes to add are what's the best order to proceed and why, and the best way to do the dip-28 legs.

	If using a solding iron (rather than hot air or a reflow oven), ~~the best~~ order ~~to solder the parts is~~:		If using a solding iron (rather than hot air or a reflow oven), go in this order:
	:1: Both resistors		:1: Both resistors first
	:2: /CS pin ~~header (~~flush-cut the posts on the bottom of the PCB)		:2: /CS and PROGRAM pin headers, flush-cut the posts on the bottom of the PCB
	:3: Legs		:3: Legs
	:4: 28C256		:4: 28C256

	~~The resistors are first simply for physical convenience, because later they are surrounded by other parts.~~		How to do the legs.

	~~You should flush-cut the back-side of the /CS pin header before installing the DIP legs, just to reduce the chance of accidentally damaging the legs later.~~

	The important thing is to do the legs before the chip, because the pads for the chip legs are close enough to the through-holes for the legs that if you do the chip before the legs, then it's easy to accidentally get solder in the holes for the legs, and that makes it difficult to install the legs later, even after you wick the solder out of the holes.

	~~So you should do the legs while the holes for the legs are still clean and new.~~

	~~Next, how~~ to do the legs.

	:Cut two sections of 14 legs off the leadframe strip. The BOM above specifies a single 28-pin strip, so if you go that, just cut that in half.		:Cut two sections of 14 legs off the leadframe strip. The BOM above specifies a single 28-pin strip, so if you go that, just cut that in half.
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	Finally install the 28C256 using the drag technique.		Finally install the 28C256 using the drag technique.

	~~If you are using hot air or a reflow oven then you should do the resistors and 28C256 first.~~

	== Programming ==		== Programming ==