OPTROM Switching - Revision history

Jhoger: /* Option ROM Code Template */

2011-08-21T05:22:32Z

Option ROM Code Template

← Older revision		Revision as of 22:22, 20 August 2011
Line 26:		Line 26:
	== Option ROM Code Template ==		== Option ROM Code Template ==

	Some time was spent in developing a good method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John ~~Hogerhius~~ and Steve Adolph, inspired by work done by Mo Budlong.		Some time was spent in developing a good method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John Hogerhuis and Steve Adolph, inspired by work done by Mo Budlong.

	The goal was to		The goal was to

2011-03-13T21:06:29Z

Option ROM Code Template

← Older revision		Revision as of 14:06, 13 March 2011
Line 207:		Line 207:


	Note that in some instances one might need to use the data stored in FF45 to ~~preseve~~ the state of ~~thinks~~ like the cassette relay. In that case, it is relatively simple to extend this to cover FF45 support properly.		Note that in some instances one might need to use the data stored in FF45 to preserve the state of things like the cassette relay. In that case, it is relatively simple to extend this to cover FF45 support properly.

	[[Category:Model T Developer Reference]]		[[Category:Model T Developer Reference]]

2010-05-28T04:28:46Z

@@ Line 7: / Line 7: @@
 fundamental facilities you need to put in place to implement a new OptROM. In order to efficiently test
 your ROM, you can use VirtualT, REX, or blow EEPROMS.
 == Option ROM Code Template ==

2010-05-28T04:19:29Z

Option ROM Code Template

← Older revision		Revision as of 21:19, 27 May 2010
Line 10:		Line 10:
	== Option ROM Code Template ==		== Option ROM Code Template ==

	Some time was spent in developing ~~an improved~~ method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John Hogerhius and Steve Adolph, inspired by work done by Mo Budlong.		Some time was spent in developing a good method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John Hogerhius and Steve Adolph, inspired by work done by Mo Budlong.

	The goal was to		The goal was to

2010-05-28T04:18:58Z

Overview

← Older revision		Revision as of 21:18, 27 May 2010
Line 5:		Line 5:

	If you are interested in creating your own OptROM, this article presents template assembly code to provide the		If you are interested in creating your own OptROM, this article presents template assembly code to provide the
	fundamental facilities you need to put in place to implement a new OptROM.		fundamental facilities you need to put in place to implement a new OptROM. In order to efficiently test
			your ROM, you can use VirtualT, REX, or blow EEPROMS.

	== Option ROM Code Template ==		== Option ROM Code Template ==

2010-05-28T04:17:41Z

Option ROM Code Template

← Older revision		Revision as of 21:17, 27 May 2010
Line 11:		Line 11:
	Some time was spent in developing an improved method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John Hogerhius and Steve Adolph, inspired by work done by Mo Budlong.		Some time was spent in developing an improved method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John Hogerhius and Steve Adolph, inspired by work done by Mo Budlong.

	The goal was to		The goal was to
	* ~~use~~ only the stack
	* ~~minimize~~ code size		* Use only the stack - no unsafe use of RAM variables
	* ~~reduce~~ execution time		* Minimize code size
			* Minimize execution time overhead

			To these ends, the code is heavily optimized, making good use of the undocumented 8085 instructions.

	<code><pre>		<code><pre>

2010-05-28T04:15:25Z

← Older revision		Revision as of 21:15, 27 May 2010
Line 1:		Line 1:
	== Overview ==		== Overview ==

			On the Model 100 (unmodified), the lower 32K is always occupied by a ROM (Read-Only Memory).
			This is either the stock "BASIC ROM" or an Option ROM (OptROM).

			If you are interested in creating your own OptROM, this article presents template assembly code to provide the
			fundamental facilities you need to put in place to implement a new OptROM.

			== Option ROM Code Template ==

	Some time was spent in developing an improved method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John Hogerhius and Steve Adolph, inspired by work done by Mo Budlong.		Some time was spent in developing an improved method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John Hogerhius and Steve Adolph, inspired by work done by Mo Budlong.
Line 7:		Line 15:
	* minimize code size		* minimize code size
	* reduce execution time		* reduce execution time

	~~== Option ROM Code Template ==~~

	<code><pre>		<code><pre>

2010-05-28T04:10:21Z

← Older revision		Revision as of 21:10, 27 May 2010
Line 182:		Line 182:

	Note that in some instances one might need to use the data stored in FF45 to preseve the state of thinks like the cassette relay. In that case, it is relatively simple to extend this to cover FF45 support properly.		Note that in some instances one might need to use the data stored in FF45 to preseve the state of thinks like the cassette relay. In that case, it is relatively simple to extend this to cover FF45 support properly.

			[[Category:Model T Developer Reference]]

2010-05-28T04:07:23Z

← Older revision		Revision as of 21:07, 27 May 2010
Line 1:		Line 1:
			== Overview ==

	Some time was spent in developing an improved method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John Hogerhius and Steve Adolph, inspired by work done by Mo Budlong.		Some time was spent in developing an improved method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John Hogerhius and Steve Adolph, inspired by work done by Mo Budlong.

Line 6:		Line 8:
	* reduce execution time		* reduce execution time

			== Option ROM Code Template ==

	<code><pre>		<code><pre>

2010-05-28T00:46:17Z

← Older revision		Revision as of 17:46, 27 May 2010
Line 1:		Line 1:
	Some time was spent in developing an improved method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John Hogerhius and Steve Adolph, ~~based on~~ work done by Mo Budlong.		Some time was spent in developing an improved method to call main ROM from option ROM, and to handle interrupts from within the optrom. This code was developed by John Hogerhius and Steve Adolph, inspired by work done by Mo Budlong.

	The goal was to		The goal was to