VisorCentral.com (http://discussion.visorcentral.com/vcforum/index.php)
- Visor General Chat (http://discussion.visorcentral.com/vcforum/forumdisplay.php?forumid=31)
-- IBM XT vs. Dragonball .... who wins? (http://discussion.visorcentral.com/vcforum/showthread.php?threadid=19521)

IBM XT vs. Dragonball .... who wins?

When I started my career back in 1991 my first computer was an IBM XT with a 386 processor with a whopping 1MB of RAM and a 20MB hard drive.

It makes me wonder how, on a comparitive basis, my VDX compares in terms of computing power. Given, the OS and the memory configuration is different, but in terms of raw computational horsepower which would be considered "more powerful"?

XT? 386? Are you sure? Did they briefly resurrect the name?

quote:

---

Originally posted by Toby
XT? 386? Are you sure? Did they briefly resurrect the name?

---

__________________
<IMG WIDTH="200" HEIGHT="50" SRC=http://www.visorcentral.com/images/visorcentral.gif> VisorCentral Discussion Moderator
Do files get embarrassed when they get unzipped?

Regardless

286....386....whatever. Where does my the VDX fit into the evolutionary timeline in terms of executed instruction sets?

The original IBM XT used an Intel 8088 running at 4.77 MHz. The 8088 has a maximum memory space of 1 Meg. The memory map of the XT left 640k for main memory. The rest being use for system ROM and memory mapped devices like the video cards. There was a memory scheme that did bank switching of memory which one could exceed the 640k limit. But programs had to be written to specifically to support it. The 8088 was a hybrid 8/16 bit processor, that is, internally it worked as a 16-bit processor, but externally it had to fetch memory and I/O 8-bits at a time. (The 8086 was 16-bit both internally and externally).

The original DragonBall processor was used in the original Palm devices, up to and including the Palm III, all running at 16MHz. The DragonBall processor has a maximum memory space of 4 Gig. (Yes, 4 Gig. All 32-address lines were available.) The memory map of the original Palm devices limited user memory to 12 Meg (this distance from the start of RAM to the start of ROM). The DragonBall processor is a hybrid 16/32-bit processor, that is, internally it works as a 32-bit processor, but externally it has to fetch memory and I/O at not more than 16-bits at a time.

The DragonBall EZ processor has been used in most Palm OS devices since, running at 16 or 20MHz. (The EZ is used in the original Visor and Visor Deluxe) The DragonBall EZ processor added some memory management circuitry to the processor that made device design easier, but limited the total memory space. From my math, I find it has a total memory space of about 96 Meg. The memory map of the Palm devices however still limited user memory to 12 Meg, but because of an EZ limitation it could only handle 8 Meg of dynamic memory in that space.

The DragonBall VZ processor is being used in the current line of Palm OS devices, running at 33 MHz. (Handspring has used the VZ in everything since the Deluxe.) The VZ improved the dynamic memory manager, and the memory map of the Palm devices apparently has been changed so that now user memory is limited to 16Meg.

Motorola has announced, a DragonBall Super VZ (or just SZ) that runs at 66MHz. No device uses this processor yet.

To summarize: Comparing a IBM XT vs. a Visor Deluxe:

• Main Memory: 640k vs. 8M
• Processor speed: 4.77MHz vs. 16MHz.
• Internal Processor data width: 16 vs. 32 bits.
• External Processor data width: 8 vs. 16 bits.

As far as lineage, the DragonBall chips are made by Motorola and are descended from the 68000 line. These are the chips that were in the original Macintoshes, Amigas, and Atari STs. Architecturally, they are much superior for the reasons given in potter's post. In addition, they have a much more advanced instruction set and the memory is addressed linearly. This means that the memory runs in one continuous chunk from beginning to end.

When I first went to work for a company that made PC based products, it was explained how the x86 memory architecture was split into 64K segments and you could only access one sement at a time, I though they were joking.

When I explained how the memory on the 68000 worked, they thought I was joking. After a while when we realized that everyone was serious, we were all just depressed.

quote:

---

Originally posted by bradhaak
As far as lineage, the DragonBall chips are made by Motorola and are descended from the 68000 line. These are the chips that were in the original Macintoshes, Amigas, and Atari STs.

---

__________________
--
ThirdMan

The Amiga had some really cool custom chips that might be too difficult to emulate with reasonable performance.

A Mac emulator might not be tough, but you would have to use pirated ROM images.

One goofball has been working on an Apple ][ emulator, but it only runs on the Clie now...
http://www.palmgear.com/software/sh...fm?prodID=16190

__________________
--
ThirdMan

quote:

---

Originally posted by potter
To summarize: Comparing a IBM XT vs. a Visor Deluxe:

• Main Memory: 640k vs. 8M
• Processor speed: 4.77MHz vs. 16MHz.
• Internal Processor data width: 16 vs. 32 bits.
• External Processor data width: 8 vs. 16 bits.

---

quote:

---

Originally posted by ToolkiT
By the looks of the other specs it probably was a true XT (Intel 8088 or 8086 or Nec V20)

---

quote:

---

Originally posted by Keefer Lucas
Fascinating stuff potter. In terms of processors would the Dragonball in my VDX be roughly comparable to a 386 chip? I think my first Evergreen system was a 386 - 16 unit.

---

Okay, now what?

Okay...what about the vaunted 33 MHz Motorola Dragonball VZ? Does this take us into something comparable to 486 class computing? My first Compaq Presario was a 486 33Mhz, sans math coprocessor (wasn't that sx vs. dx designation?).

Boy I wish you could load AmiPro on a Visor. Seven years later and I still miss AmiPro. But thats another string.

Re: Okay, now what?

quote:

---

Originally posted by Keefer Lucas
Okay...what about the vaunted 33 MHz Motorola Dragonball VZ? Does this take us into something comparable to 486 class computing? My first Compaq Presario was a 486 33Mhz, sans math coprocessor (wasn't that sx vs. dx designation?).

---

quote:

---

Boy I wish you could load AmiPro on a Visor. Seven years later and I still miss AmiPro. But thats another string.

---